KR100852369B1 - Electrophoretic display device and driving method for same - Google Patents

Abstract

An electrophoretic display device capable of preventing afterimage and image burn-in is disclosed. The frame for driving the electrophoretic element and the microcapsule type electrophoretic display constituting the active matrix is divided into a plurality of white frames and black frames. The number of white frames used to record on an electrophoretic device using a scanning driver and a data driver on a picture or between pictures becomes equal to the number of black frames used to record and for changes in the electric field. The recording of frames for particles with slow mobility is provided at the end of the formation of the screen.

Electrophoresis, intermediate potential, afterimage, burn-in

Description

Electrophoretic display and its driving method {ELECTROPHORETIC DISPLAY DEVICE AND DRIVING METHOD FOR SAME}

1 is a schematic circuit diagram showing a configuration of a drive circuit of an electrophoretic display device according to a first embodiment of the present invention.

Fig. 2 is a schematic circuit diagram showing the configuration of a data driver of an electrophoretic display device according to a first embodiment of the present invention.

3 is a diagram showing driving waveforms of a data driver of an electrophoretic display device according to a first embodiment of the present invention;

Fig. 4 is a schematic diagram illustrating an effect obtained when a black state is inserted into a transition state between a white state and a continuous white state in a driving operation performed in the electrophoretic display device according to the first embodiment of the present invention.

Fig. 5 is a diagram showing a change in display state in driving an electrophoretic display device according to a first embodiment of the present invention.

FIG. 6 is a view used to explain a state in which a second afterimage is generated in the electrophoretic display device according to the first embodiment of the present invention; FIG.

7 is a view used to explain a state in which a second afterimage disappears in the electrophoretic display according to the first embodiment of the present invention.

Fig. 8 is a diagram showing the relationship between the voltage of the counter electrode and the voltage of the pixel electrode in driving the electrophoretic display device according to the first embodiment of the present invention.

Fig. 9 is a diagram showing waveforms of voltages applied to counter electrodes in driving an electrophoretic display device according to a second embodiment of the present invention.

10 is a diagram showing a change in driving an electrophoretic display device according to a third embodiment of the present invention;

FIG. 11 is a diagram showing waveforms for explaining driving of an electrophoretic display device according to a third embodiment of the present invention; FIG.

12 is a time chart for explaining a luminance state in the electrophoretic display device according to the first and second embodiments of the present invention.

FIG. 13 is a time chart illustrating a luminance state in an electrophoretic display device according to a third embodiment of the present invention. FIG.

Fig. 14 is a schematic diagram showing the structure of a drive circuit of a microcapsule type electrophoretic display device according to a fourth embodiment of the present invention.

Fig. 15 is a schematic diagram showing the structure of a data driver of a microcapsule type electrophoretic display device according to a fourth embodiment of the present invention.

Fig. 16 is a diagram showing a change in driving the microcapsule type electrophoretic display device according to the fourth embodiment of the present invention.

17A and 17B show a relationship between an afterimage and an applied voltage in a microcapsule type electrophoretic display device according to a fourth embodiment of the present invention.

FIG. 18 is a view showing waveforms for explaining driving of a microcapsule type electrophoretic display device according to a fourth embodiment of the present invention; FIG.

Fig. 19 is a diagram showing a change of display state in driving a microcapsule type electrophoretic display device according to a fifth embodiment of the present invention.

20 is a time chart for explaining driving of a microcapsule type electrophoretic display device according to a fifth embodiment of the present invention;

Fig. 21 is a diagram showing a change in driving the microcapsule type electrophoretic display device according to the sixth embodiment of the present invention.

Fig. 22 is a diagram showing waveforms for explaining driving of a microcapsule type electrophoretic display device according to a sixth embodiment of the present invention.

23 is a time chart illustrating the disadvantages of the fourth and fifth embodiments.

24 is a time chart illustrating the advantages of the sixth embodiment of the present invention.

25 is an enlarged cross-sectional view conceptually showing the configuration of a conventional microcapsule type electrophoretic display panel.

Fig. 26 is a schematic circuit diagram of a microcapsule type element arranged in matrix form constituting a conventional electrophoretic display device.

Fig. 27 is a schematic circuit diagram showing a drive circuit of a conventional electrophoretic display device.

Fig. 28 is a schematic circuit diagram showing part of the configuration of a data driver of a conventional electrophoretic display device.

29 is a diagram showing a drive waveform of a data driver of a conventional electrophoretic display.

30 is a state change diagram illustrating driving of a conventional electrophoretic display device.

FIG. 31 is a view for explaining a first afterimage problem of the conventional electrophoretic display. FIG.

32 is a time chart for explaining a first afterimage problem of the conventional electrophoretic display.

33 illustrates a second afterimage problem of a conventional electrophoretic display.

34 is a cross-sectional view of a panel of a conventional electrophoretic display device, illustrating a second afterimage problem.

The present invention relates to an electrophoretic display and a driving method thereof, and more particularly to an electrophoretic display and an electrophoretic display capable of providing excellent display by preventing afterimage and / or image burn-in. It relates to a device driving method.

This application claims priority to Japanese Patent Application No. 2005-362318 filed December 15, 2005 and Japanese Patent Application No. 2005-378274 filed December 28, 2005, which are incorporated herein by reference.

One example of an electronic display that enables the naked eye to read e-books, electronic newspapers, etc. without causing eye fatigue is an electronic paper display that is being actively developed. The requirements for electronic paper displays are thin, light, resistant to cracks, and easy to see at the print level. As a display device capable of satisfying these requirements, a reflective display configured to consume less power without using a backlight is commercially available.

Examples of reflective displays that do not use polarizers are electrophoretic displays (herein referred to as "EPD") and the like. Several types of EPDs exist, and hereinafter, EPDs using microencapsulated electrophoretic devices (also referred to simply as "electrophoretic elements") are described.

25 is an enlarged cross-sectional view conceptually showing the configuration of an electrophoretic display panel, specifically an enlarged cross-sectional view of a black and white microcapsule type electrophoretic device arranged in an m-row and n-column matrix. In the electrophoretic display panel, as shown in Fig. 25, each microcapsule-type element is composed of a TFT (thin film transistor) glass substrate 102, an electrophoretic film 110, and a PET (polyethylene terephthalate) counter substrate 120 in this order. Stacked to form a stacked structure functioning to enable an active matrix drive of the electrophoretic display device, for example, microcapsule type electrophoretic elements 100-m1, 100-m2 and 100-m3 are formed in m rows. do.

On the TFT glass substrate 102, TFTs 104-m1, TFTs 104-m2 and TFTs 104-m3 corresponding to the respective electrophoretic elements 100-m1, 100-m2 and 100-m3. Pixel electrodes 106-m1, 106-m2 and 106-m3 connected to respective TFTs 104-m1, 104-m2 and 104-m3, respectively, and respective pixel electrodes 106-m1, 106-m2 And storage electrodes 108-m1, 108-m2 and 108-m3 formed to face 106-m3. Therefore, the microcapsule type electrophoretic display device is configured to display an image by an active matrix driving method. In the polymeric binder 112 housed in the electrophoretic membrane 110, microcapsules having a size of about 40 μm are diffused in the binder 112 as a whole. Conventionally, each microcapsule 114 is smaller by a predetermined value than the size of the pixel electrode of the microcapsule type electrophoretic display device. Dispersant 116 is injected into each microcapsule 114, into which negatively charged nano-level sized white pigment particles (white particles, for example titanium oxide; 117) and positively charged nano-level size Black pigment particles (black particles, for example carbon; 118) are suspended. In the PET counter substrate 120, one counter electrode 122 facing the pixel electrodes 106-m1, 106-m2 and 106-m3 formed on the TFT glass substrate 102 is fixed to the plastic substrate 124. It is. Therefore, each microencapsulated electrophoretic element 100-m1, 100-m2 and 100-m3 has a TFT 104-m1, corresponding to each pixel electrode 106-m1, 106-m2 and 106-m3. 104-m2 and 104-m3), microcapsules 114 and corresponding portions of the counter electrode 122.

FIG. 26 is a schematic circuit diagram of a microcapsule type electrophoretic element arranged in a matrix and planar form, which form a microcapsule type electrophoretic display device (herein simply referred to as "electrophoretic display device"). In FIG. 26, the same reference numerals are given to components having the same functions as in FIG. In Fig. 26, the data line Dn is electrophoretic elements (100-mn (m = 1,2, ..., M, n = 1,2, ...) arranged in a matrix form constituting the electrophoretic display device. .., N)) represents a line used for supplying a display data signal to each of the electrophoretic elements 100-mi (i = 1,2, ..., N) arranged in the horizontal direction. Further, the scanning line Gm is an electrophoretic element 100-m1, 100-m2, ..., arranged in a horizontal direction among the electrophoretic elements 100-mn arranged in a matrix form constituting the electrophoretic display device. 100-mN) represents a line used to supply the scanning voltage for one scanning period.

27 is a schematic circuit diagram showing a drive circuit 140 of a conventional electrophoretic display device. The driving circuit 140 continuously applies a scanning voltage to each of the group of electrophoretic elements 100-m1, 100-m2, ..., 100-mN arranged horizontally among the electrophoretic elements arranged in a matrix form. Continuously supplying display data signals through respective data lines Dn to each of the scanning driver 142 and the electrophoretic elements 100-mi arranged horizontally among the matrix-type electrophoretic elements. Data driver 144 for each other. 28 is a schematic circuit diagram showing the data signal generation circuit 145 for the individual data lines Dn, which constitute the data driver 144. The data signal generation circuit 145 supplies a voltage corresponding to the selection signal output from the selection signal generation circuit 146 and the selection signal generation circuit 146 to generate the selection signal in response to the picture data (data line Dn). ), And a voltage selection circuit 147 outputting to the circuit.

In the electrophoretic display device having the above-described configuration, a voltage is applied to the pixel electrode 106-mn constituting the microcapsule type electrophoretic element 100-mn in a manner as described below, and to the screen of the electrophoretic display device. An image corresponding to the input screen data is displayed on the screen.

When the electrophoretic element 100-mn corresponding to the pixel on the screen of the electrophoretic display device is configured to function as a unit for displaying a white state (hereinafter simply referred to as “W”), the electrophoretic element 100-mn A negative voltage is output to the constituent pixel electrodes 106-mn; That is, a voltage of, for example, -15 V corresponds to the number of frames required from the data driver 144 to the data line Dn of the data driver 144 connected to the data line, for example the pixel electrode 106-mn. Is output during the cycle. Referring to this operation with reference to Fig. 28, the selection signal generation circuit 146 which receives the screen data is negatively connected to the selection line corresponding to the pixel, for example the selection line 152-n, during the period in which the pixel is operated. Output the voltage of. This causes the pMOS (p-channel metal oxide semiconductor) transistor constituting the voltage selection circuit 147, for example pMOS 154-n, to be turned ON, and a voltage of -15V to be output to the data line Dn.

Further, when the electrophoretic element corresponding to the pixel on the screen of the electrophoretic display device is configured to function as a unit displaying black (hereinafter simply referred to as "B"), the pixel electrode 106-mn constituting the electrophoretic element Positive voltage is output; That is, for example, the required number of frames from the data driver 144 to the data line Dn of the data driver 144 connected to the data line, for example, the pixel electrode 106-mn, is provided. Outputted during the displayed period. Referring to Fig. 28, the selection signal generation circuit 146 for receiving the screen data is negatively connected to the selection line corresponding to the pixel, for example the selection line 156-n, during the period in which the pixel is operated. Output the voltage of. This causes the pMOS (p-channel metal oxide semiconductor) transistor constituting the voltage selection circuit 147, for example pMOS 158-n, to be turned ON, and a voltage of + 15V to be output to the data line Dn.

In an electrophoretic display device displaying an image in black and white, due to the memory characteristics of the electrophoretic element, electrophoresis corresponding to a pixel to which the display should be switched when the display of the pixel is switched from W to B or from B to W The application of the voltage as described above to the pixel electrode of the element 100-mn should be switched, but basically no application of voltage to the pixel is required when the display of the pixel is switched from W to W and from B to B.

Next, the driving of such an electrophoretic display device analyzed by the inventor of the present invention will be described. As described above, a positive voltage must be applied to the pixel electrode when the display of the pixel in the electrophoretic film 110 changes from W to B, and a negative voltage is applied to the pixel electrode when the display of the pixel changes from B to W. If the display of the pixel changes from W to W or from B to B, a voltage of 0V should be applied.

In addition, in the case of an active matrix display device such as a liquid crystal display, the screen may be rewritten for a period corresponding to one frame of 1/60 Hz (= 16.6 ms). However, in the case of an electrophoretic display, it is impossible to update the screen for a period corresponding to 1 frame of 1/60 Hz (= 16.6 ms). The reason is that in the microcapsule type electrophoretic device constituting the electrophoretic display, the particles 117, 118 are sealed in the microcapsule filled with the dispersant and the particles 117, 118 therein react slowly, so that a plurality of This is because the screen cannot be updated unless voltage is continuously applied during the period in which the frame is displayed. In general, therefore, in an electrophoretic display device, as shown in FIG. 29, when a display of a pixel is changed from B to W, a specific negative voltage is continuously applied for a period corresponding to a plurality of frames and the display of the pixel is W. FIG. Pulse Width Modulaton (PWM) driving method is employed in which a certain amount of voltage is continuously applied during a period corresponding to a plurality of frames when changing from B to B.

In the conventional electrophoretic display device, in order to achieve a driving method as shown in FIG. 29, a difference between a voltage applied to the current screen and a voltage applied to the next screen stored in a frame buffer composed of static random access memory (SRAM) Is calculated, and a corresponding voltage is applied based on the voltage difference calculated for the period corresponding to the plurality of frames when the display of the pixel is changed from B to W and from W to B. To apply these voltages, a ternary (+ V, 0V and -V) driver is used as the H-driver and Vcom is set to 0V. The change of screen display from B to W and from W to B is made at the time when the corresponding frame is displayed.

However, a more detailed analysis by the present inventors shows that the above-mentioned conventional electrophoretic display device has a technical problem. That is, when the conventional microcapsule type electrophoretic device is driven by the driving method described in FIG. 30, when the microcapsule type electrophoretic device without voltage is applied to the pixel electrode, the white luminance is reduced or An increase in black brightness has been found, which is not only in the memory characteristics of the microencapsulated electrophoretic device, but also in the DC (direct current) included in the gate potential and / or data line of the microencapsulated device or in the common potential of the counter electrode. It is due to ingredients. As a result, when the display is switched from W to W and from B to B, a difference in white luminance occurs (see FIGS. 31 and 32), and the current screen remains continuously while the next screen is displayed. 1 An afterimage problem occurs. The same problem occurs when the display changes from B to B and from W to B.

Further, when a high resolution e-book display terminal device is manufactured, when a dither pattern is displayed at two gray levels, or when an image is made to have a color, the pixel pitch should be set to 150 μm or less. However, it has been found that when the pixel pitch is narrowed, the microcapsule type electrophoretic device is affected by the pixel voltage applied to the adjacent microcapsule electrophoretic device. Specifically, when the pattern of the current image is displayed in black and the pattern of the next image is displayed as a checkered pattern to display the dither pattern at 2 gray levels, the black display area of the screen is damaged, that is, prepared for the original pixel. The displayed display area is reduced. When black characters in an area form are displayed on a current screen and a dither pattern is displayed on a next screen, a second afterimage problem in which a character displayed on the current screen is continuously left on the next screen occurs.

According to the conventional driving method, since the pixel voltage is not applied to the pixel for the "NTL" character displayed in black on the current screen shown in FIG. 33 and the pixel for the dither pattern displayed in black on the next screen, the pixel electrode is 100. In the case of fine and small patterns having a size of 탆 to 150 탆, a voltage applied to an adjacent pixel for white display is input to a pixel to which no voltage is applied, and as a result, to the surface of the microcapsule disposed at the pixel electrode of the adjacent pixel. This problem was found to occur because white particles appeared (see FIG. 34).

As mentioned above, the display of the screen changes sequentially, for example, from B to W, from W to B, and from B to W, positive or negative of + 15V, -15V, + 15V and -15V. When a voltage of is applied to the pixel electrodes of the pixels alternately, no DC current is thereby applied to the electrophoretic element. However, if the display on the screen changes continuously from B to B and from B to B and from B to B and a voltage of +15 V is applied to the pixel electrode for a period corresponding to multiple frames, or the display on the screen is W Is continuously changed from W to W and from W to W and from W to W and a voltage of -15 V is continuously applied to the pixel electrode during a period corresponding to a plurality of frames, the resulting +15 V above Or a positive or negative DC potential is continuously applied continuously to the electrophoretic element to which -15V is applied. Therefore, even when charge-up damage occurs in the electrophoretic film and the display of the image is terminated by the application of 0V, it is found that the inverted image displayed only on the charging part is still displayed, causing image burn-in. It became.

In view of the above, it is an object of the present invention to provide an electrophoretic display device capable of preventing afterimage and image burn-in.

According to a first aspect of the present invention, there is provided an electrophoretic panel and a potential difference applying unit.

The electrophoretic panel includes a plurality of signal lines extending parallel to each other in a first direction, a plurality of scanning lines extending parallel to each other in a second direction perpendicular to the first direction, and a plurality of pixel electrodes as electrophoretic elements. A first substrate arranged in a one-to-one relationship corresponding to each intersection of one of the lines and one of the scanning lines,

A second substrate having a transparent counter electrode opposite the plurality of pixel electrodes, and

A first color charged particle having a first color and a first polarity and movably sandwiched between each of the plurality of pixel electrodes and the transparent counter electrode such that the pixels are arranged in a matrix form and a second color having a second color and a second polarity Contains charged particles,

The potential difference applying unit is configured such that when each of the plurality of screens including the first pattern having the first color and the second pattern having the second color is displayed in the display area of the electrophoretic display panel, Applying a potential difference corresponding to each of the first color and the second color during a period corresponding to a predetermined number of frames between at least one corresponding pixel electrode and the transparent counter electrode,

A first unit for providing a first frame group consisting of a predetermined number of first frames and corresponding to a first color and a second frame group consisting of a predetermined number of second frames and corresponding to a second color in a predetermined order for each screen. ; And

In displaying the screen, when the first frame group is generated by the first unit, a potential difference corresponding to the first color for the first frame group is applied between each of the pixel electrodes corresponding to the first pattern and the transparent counter electrode. And a second unit for applying a potential difference corresponding to the second color for the second frame group between each of the pixel electrodes corresponding to the second pattern and the transparent counter electrode when the second frame group is generated by the first unit. Provided is an electrophoretic display device.

Preferably, the second unit is configured to obtain a given screen between each of the corresponding pixel electrodes and the counter electrode when any one of the first and second colors to be displayed on the given screen should be displayed continuously on the subsequent screen. A third applying a potential difference corresponding to the other of the first and second colors in a transition state between any one of the provided first and second frame groups and any one of the provided frame groups to obtain a subsequent picture; The unit further includes a third unit, wherein the potential difference corresponds to another color that is opposite in polarity to the potential difference corresponding to any one color and is applied for a period corresponding to another frame group in the first frame group and the second frame group. do.

Also preferably, the number of frames required for the second unit to cause one or more of the pixel electrodes as the electrophoretic element to display any one of the first and second colors on a given screen is equal to any one color. One or more of the pixel electrodes displayed on a given screen includes a fourth unit that is approximately equal to the number of frames required to display different colors on subsequent screens.

Also preferably, the fourth unit comprises a number T1 of frames required to cause the one or more pixel electrodes to display any one color on the first screen, one or more pixel electrodes that display any one color on the first screen. Number of frames required to cause different colors to be displayed on the second screen subsequent to the first screen T2, one or more pixel electrodes displaying different colors on the second screen display different colors on the third screen subsequent to the second screen Between the number of frames T3 necessary to make it necessary, and the number of frames T4 required to cause one or more pixel electrodes displaying different colors on the third screen to display any one color on the fourth screen subsequent to the third screen. ,

T2 + T3 = T1 + T4

It drives to hold.

Also preferably, the second unit is configured to move one frame group of the first frame group and the second frame group to move the charged particles having slow mobility toward the counter electrode in response to the change of the electric field to form the last frame in forming the screen. And a fifth unit for setting as a group.

Also preferably, the second unit transitions the intermediate potential difference between the potential difference applied before switching of the screen and the potential difference applied after switching when the potential difference between one or more of the pixel electrodes and the counter electrode changes during the switching of the screen. And a sixth unit for applying in a state.

Also preferably, the sixth unit is an intermediate potential difference applied between at least one of the pixel electrodes and the counter electrode when at least one of the pixel electrodes switches the display from any one of the first and second colors to another color. The number of frames T1 applying V1 and the number of frames applying the intermediate potential difference V2 applied between one or more of the pixel electrodes and the counter electrode when one or more of the pixel electrodes switches the display from one color to any one color. The following formula between T2,

V1 x T1 = V2 x T2

It is configured to hold.

Also preferably, in the electrophoretic display panel, each pixel electrode on the first substrate is connected to each signal line through a respective gate element controlled by a signal supplied from each scanning line, and the second substrate is A dispersant sealed in each capsule dispersed in a binder between the first substrate and the second substrate, having a one-piece transparent counter electrode facing the entire area of the first substrate, wherein the first color charged particles and the second color charged particles Floating in

Also preferably, the first color comprises either black and white and the second color comprises the other of black and white.

Also preferably, the second unit used to apply the potential difference is a ternary driver which fixes the potential of the counter electrode to the reference potential and changes the potential of the pixel electrode by the potential difference from the reference voltage.

Also preferably, the second unit used to apply the potential difference changes the potential of the counter electrode by the potential difference from the reference potential according to the first color or the second color and between the counter electrode and the pixel electrode in accordance with the potential change of the counter electrode. The potential of the pixel electrode is changed to generate a potential difference corresponding to the first color or the second color at.

According to a second aspect of the present invention, there is provided a method of driving an electrophoretic display device comprising an electrophoretic panel,

The electrophoretic panel includes a plurality of signal lines extending parallel to each other in a first direction, a plurality of scanning lines extending parallel to each other in a second direction perpendicular to the first direction, and a plurality of pixel electrodes as electrophoretic elements. A first substrate arranged in a one-to-one relationship corresponding to each intersection of one of the lines and one of the scanning lines,

A second substrate having a transparent counter electrode opposite the plurality of pixel electrodes, and

A first color charged particle having a first color and a first polarity and movably sandwiched between each of the plurality of pixel electrodes and the transparent counter electrode such that the pixels are arranged in a matrix form and a second color having a second color and a second polarity Contains charged particles,

One corresponding to each of the first pattern and the second pattern when each of the plurality of screens including the first pattern having the first color and the second pattern having the second color is displayed in the display area of the electrophoretic display panel A potential difference corresponding to each of the first color and the second color is applied between the above pixel electrode and the transparent counter electrode for a period corresponding to a predetermined number of frames,

A method of driving an electrophoretic display device including an electrophoretic display panel includes a first frame group consisting of a predetermined number of first frames and corresponding to a second color and a first frame group corresponding to a first color. Providing a second frame group for each screen in a predetermined order; And

In displaying the screen, when the first frame group is generated by the first unit, a potential difference corresponding to the first color for the first frame group is applied between each of the pixel electrodes corresponding to the first pattern and the transparent counter electrode. And applying a potential difference corresponding to the second color for the second frame group between each of the pixel electrodes corresponding to the second pattern and the transparent counter electrode when the second frame group is generated by the first unit. A driving method of an electrophoretic display device is provided.

According to a third aspect of the invention, there is provided an electrophoretic panel and a potential difference applying unit,

The electrophoretic panel includes a plurality of signal lines extending parallel to each other in a first direction, a plurality of scanning lines extending parallel to each other in a second direction perpendicular to the first direction, and a plurality of pixel electrodes as electrophoretic elements. A first substrate arranged in a one-to-one relationship corresponding to each intersection of one of the lines and one of the scanning lines,

A second substrate having a transparent counter electrode opposite the plurality of pixel electrodes, and

A first color charged particle having a first color and a first polarity and a second color having a second color and a second polarity such that the pixels are arranged in a matrix and movably sandwiched between each of the plurality of pixel electrodes and the transparent counter electrode Contains color charged particles,

The potential difference applying unit includes a plurality of screens each including a first pattern having a first color, a second pattern having a second color, and at least one halftone pattern having a midtone color between the first and second colors. When displayed in a display area of an electrophoretic display panel, a first color, a second color, for a period corresponding to a predetermined number of frames between at least one pixel electrode corresponding to each of the first pattern and the second pattern and the transparent counter electrode And applying a potential difference corresponding to each of the one or more halftone patterns,

A first unit for generating a plurality of frame groups composed of a predetermined number of predetermined frames per screen, and outputting a potential difference for each of the first color, the second color, and the mid-tone color to be displayed in the display area in a predetermined order; and

In any one of the plurality of frame groups continuously generated by the first unit in displaying a screen, a frame group between each of the pixel electrodes and the counter electrode corresponding to the first pattern, the second pattern or the one or more halftone patterns An electrophoretic display device is provided, including a second unit for applying each potential difference.

Preferably, the second unit is configured to counter each of the corresponding pixel electrodes and the counter electrode when any one of the first color, the second color and the one or more halftone colors to be displayed on a given screen should be displayed successively on subsequent screens. Between, any one color group corresponding to any one color provided to obtain a given picture and any potential color corresponding to another color different from any one color in transition state between any one frame group provided to obtain a subsequent picture And a third unit for applying a potential, wherein the potential difference further applies a third unit applied for a period of time corresponding to another color group which is opposite in polarity to the potential difference corresponding to any one color and corresponding to another frame group different from any one frame group. Include.

Also preferably, in the second unit, the number of frames required to apply a predetermined potential difference to one or more of the pixel electrodes as electrophoretic elements on a given screen is equal to a predetermined potential difference to one or more pixel electrodes to which the predetermined potential difference is applied on a subsequent screen. And a fourth unit that is approximately equal to the number of frames needed to apply an opposite potential difference having an opposite polarity with.

Also preferably, the fourth unit may include a number T1 of frames required to apply a predetermined potential difference to one or more pixel electrodes on the first screen, and one or more pixel electrodes to which a predetermined potential difference is applied on the second screen subsequent to the first screen. The number of frames T2 required to apply an opposite potential difference having a polarity opposite to the predetermined potential difference, the number of frames T3 required to continuously apply the opposite potential difference to one or more pixel electrodes to which the opposite potential difference is applied on the third screen subsequent to the second screen. And between the number of frames T4 required to apply a predetermined potential difference to at least one pixel electrode to which an opposite potential difference is applied on a fourth screen subsequent to the third screen.

T2 + T3 = T1 + T4

It drives to hold.

Also preferably, the second unit is configured to set one frame group of the plurality of frame groups, which moves charged particles having slow mobility toward the counter electrode in response to the change in the electric field, to the last frame group when the screen is formed. It includes more units.

Also preferably, the second unit transitions the intermediate potential difference between the potential difference applied before switching of the screen and the potential difference applied after switching when the potential difference between one or more of the pixel electrodes and the counter electrode changes during the switching of the screen. And a sixth unit for applying in a state.

Also preferably, the sixth unit is configured to switch the pixel electrode when one of the pixel electrodes switches the display from any one of the first color, the second color and the one or more halftone colors to another color different from any one color. The number of frames T1 applying the intermediate potential difference V1 applied between at least one of the two and the counter electrode, and between one of the pixel electrodes and the counter electrode when one of the pixel electrodes switches the display from another color to any one color. Between the number T2 of frames to which the intermediate potential difference V2 is applied,

V1 x T1 = V2 x T2

It is configured to hold.

Also preferably, in the electrophoretic display panel, each pixel electrode on the first substrate is connected to each signal line through each gate element controlled by a signal from each scanning line, and the second substrate It has a piece of transparent counter electrode opposite the entire area of the first substrate, the first color charged particles and the second color charged particles in a dispersant sealed in each capsule dispersed in a binder between the first and second substrates. Wealthy

Also preferably, the first color comprises one of black and white, the second color comprises the other one of black and white and the one or more middle tone colors comprise gray.

Also preferably, the first color comprises any one of black and white, the second color comprises the other one of black and white and the midtone color comprises light gray and dark gray do.

Also preferably, the switching of the display between the light gray and the dark gray is performed in such a manner that a white display is inserted between the display of the light gray and the display of the dark gray.

According to a fourth aspect of the present invention, there is provided a method of driving an electrophoretic display device comprising an electrophoretic panel and a potential difference applying unit,

The electrophoretic panel includes a plurality of signal lines extending parallel to each other in a first direction, a plurality of scanning lines extending parallel to each other in a second direction perpendicular to the first direction,

And a first substrate in which a plurality of pixel electrodes as electrophoretic elements are arranged in a one-to-one relationship corresponding to each intersection of one of the signal lines and one of the scanning lines,

A second substrate having a transparent counter electrode opposite the plurality of pixel electrodes, and

A first color charged particle having a first color and a first polarity and movably sandwiched between each of the plurality of pixel electrodes and the transparent counter electrode such that the pixels are arranged in a matrix form and a second color having a second color and a second polarity Contains charged particles,

The potential difference applying unit includes a plurality of screens each including a first pattern having a first color, a second pattern having a second color, and at least one halftone pattern having a midtone color between the first and second colors. When displayed in a display area of an electrophoretic display panel, a first color, a second color, for a period corresponding to a predetermined number of frames between at least one pixel electrode corresponding to each of the first pattern and the second pattern and the transparent counter electrode And a potential difference corresponding to each of the one or more halftone patterns,

The electrophoretic display driving method generates a plurality of frame groups composed of a predetermined number of predetermined frames per screen, and sets the potential difference for each of the first color, the second color, and the halftone color to be displayed in the display area in a predetermined order. Outputting, and

In any one of the plurality of frame groups continuously generated by the first unit in displaying a screen, a frame group between each of the pixel electrodes and the counter electrode corresponding to the first pattern, the second pattern or the one or more halftone patterns Applying each potential difference.

According to the above configuration, a plurality of pixels (electrophoretic elements) arranged in a matrix form have a screen composed of a pattern having one color and a pattern having one of two colors to be displayed in a pixel on the display area of the electrophoretic display device. When it should be displayed, a frame group corresponding to one color and a frame group corresponding to another color are provided in a predetermined order, and when the continuously generated frame group functions as a frame group having one of two colors, the frame group A potential difference corresponding to the color of is applied between the counter electrode and the pixel electrode corresponding to the pixel for the pattern, so that the pixel electrode and the counter electrode of the electrophoretic element on one screen or between the screens satisfy a display purpose on the screen. The potential difference applied to can be freely applied. As a result, afterimage and / or image burn-in can be prevented.

According to the above other arrangement, a screen of a pattern having two different colors and a mid-tone color between these colors is displayed on the pixels of the display area of the electrophoretic display panel with a plurality of pixels (electrophoretic elements) arranged in a matrix form. When applied, the potential difference corresponding to the frame in the frame group and frames continuously provided for display on the screen corresponds to the pixel of the pattern to be displayed by the frame such that the electrophoretic element outputs the potential difference for all the colors to be displayed. It is possible to apply a potential difference between the pixel electrode and the counter electrode in one screen or between screens by being applied between the pixel electrode and the counter electrode. As a result, after-images and / or image burn-in can be prevented when a pattern composed of white, black and intermediate tones between white and black is displayed.

The above, and other objects, advantages and features of the present invention will become apparent from the following description in conjunction with the accompanying drawings.

Best Mode for Carrying Out the Invention The best mode for carrying out the present invention will be described in more detail with reference to the accompanying drawings using various embodiments.

1st Embodiment

1 is a schematic circuit diagram showing a configuration of a drive circuit of an electrophoretic display device of a first embodiment of the present invention. 2 is a schematic circuit diagram showing the configuration of a data driver 14A of the electrophoretic display device 10A according to the first embodiment. 3 is a diagram showing a drive waveform of the data driver 14A of the electrophoretic display device 10A according to the first embodiment. FIG. 4 is a schematic diagram illustrating an effect obtained when a black state is inserted into a transition state between a white state and a subsequent white state in a driving operation performed in the electrophoretic display apparatus 10A according to the first embodiment. FIG. 5 is a diagram showing a change in display state in driving the electrophoretic display device 10A according to the first embodiment. FIG. 6 is a view used to describe a state in which a second afterimage is generated in the electrophoretic display device 10A according to the first embodiment of the present invention. FIG. 7 is a diagram illustrating a state in which the second afterimage disappears in the electrophoretic display device 10A according to the first embodiment. FIG. 8 is a diagram showing a relationship between the voltage of the counter electrode and the voltage of the pixel electrode in driving the electrophoretic display device 10A according to the first embodiment.

In the active matrix drive type electrophoretic display device 10A of the present embodiment, a frame constituting a screen is divided into a plurality of white frames and a plurality of black frames, and is used for white recording in and between images. The number of times is equal to the number of frames being used for black recording, and the frames for particles with slow mobility in response to changes in the electric field are configured to be provided last at the time of forming a given picture. As shown in Fig. 1, the electrophoretic display device 10A is a microcapsule type electrophoretic element 100-mn (m = 1, 2, ..., M; n = 1, 2, ..., N)) is configured to be driven by the scanning driver 12A and the data driver 14A. The configuration of the electrophoretic display panel itself is the same as that of the conventional electrophoretic display panel shown in FIG. Therefore, the same reference numerals are assigned to components having the same functions as those in the conventional electrophoretic display panel shown in FIGS. 6 and 7 and their description is omitted. The electrophoretic element 100-mn entirely constitutes an electrophoretic display panel. The electrophoretic element 100-mn is connected to the scanning line Gm and the data line Dn through the TFT gate 104-mm. When the TFT gate 104-mn is composed of a p-MOS transistor, the scanning driver 12A functions as a driver for outputting a gate voltage to the scanning line Gm. The data driver 14A is a data line Dn, which can prevent the application of a DC voltage to the electrophoretic element 100-mn in the total frame required to rewrite the pixels constituting the electrophoretic element 100-mn. Outputs a time series voltage.

As shown in Fig. 2, the data driver 14A includes a select signal generation circuit 26A and a voltage select circuit 28A. The selection signal generation circuit 26A allows time series voltages including + 15V (voltage used for black recording), 0V and -15V (voltage used for white recording) to be output from the voltage selection circuit 28A. Outputs a selection signal. The voltage selection circuit 28A sends a time series voltage determined according to the selection signal to the data line Dn. The selection signal is determined in accordance with the pixel data in each screen for the image, and is switched in accordance with the pixel data in each screen. That is, each screen is composed of a predetermined number of black frames and a predetermined number of white frames. In each screen, a selection signal that causes the transition from W to W and from B to B and the subsequent transition from B to W and from W to B between the screens is generated to satisfy the conditions described below (see FIG. 3). .

That is, if the electrophoretic element (100-mn) is driven with W repeatedly and continuously displayed on a given screen (for continuous display of W-> W-> W ...), on the screen By providing a predetermined number of white frames, but before or after the white frame is provided (e.g., between the white frame for obtaining a given picture and the white frame for obtaining a subsequent picture), the black frame (as a transition frame) W is recorded so that the change of display to B is made in an insert manner; That is, B is recorded by providing a white frame on the screen and providing a black frame before W is recorded, or B is recorded by providing a white frame and providing a black frame after W is recorded (Fig. ) Reference). In this case, the voltage applied to the pixel electrode 106-mn of the electrophoretic element 100-mn when B is written is set to V + = + 15V, and the electrophoretic element 100-mn when W is written. The voltage applied to the pixel electrode 106-mn of is set to V- = -15V, the number of white frames is set to Tww- and the number of black frames is set to Tww +. At this time, the setting must satisfy the following equation:

Tww + = Tww-... (One)

In addition, when the electrophoretic element 100-mn is driven with B repeatedly and continuously displayed on a given screen (for continuous display of B-> B-> B ...), By providing a predetermined number of black frames, but before or after the black frame is displayed (e.g., between a black frame for obtaining a given picture and a black frame for obtaining a subsequent picture), a white frame (as a transition frame). By providing B is recorded, and the display change to W is made in an insert manner; That is, W is recorded by providing a black frame on the screen and providing a white frame before B is recorded, or W is recorded by providing a black frame and providing a white frame after B is recorded (Fig. 4 (4 ) Reference). In this case, the voltage applied to the pixel electrode 106-mn of the electrophoretic element 100-mn when the display is switched to B is set to V + = + 15V, and the electrophoretic element ( The voltage applied to the pixel electrode 106-mn of 100-mn) is set to V-=-15V, the number of white frames is set to Tbb- and the number of black frames is set to Tbb +. At this time, the setting must satisfy the following equation:

Tbb + = Tbb-... (2)

In addition, when a display change from W to B is made on the current screen and a display change from B to W is made on the next screen, it is applied to the electrophoretic element 100-mn when W is recorded in the display change from W to B. The voltage is set to V- = -15V and the voltage applied to the electrophoretic element (100-mn) when B is recorded in the transition from W to B is set to V + = + 15V and used when W is recorded. The number of white frames to be set is Twb (-) and the number of black frames used when B is recorded is set to Twb (+), and the electrophoretic element when B is recorded in the display switching from B to W. The voltage applied to (100-mn) is set to V + = + 15V and the voltage (V-) applied to electrophoretic element 100-mn when W is recorded in the display change from B to W is V- = Set to -15V. Under these conditions, the following formula holds:

Twb (+) + Tbw (+) = Tbw (-) + Twb (-). (3)

Next, the operation of the electrophoretic display device 10A of the first embodiment will be described with reference to FIGS. 1 to 7. In the present embodiment, each electrophoretic element 100-mn constituting the electrophoretic display device 10A is changed from a means for displaying W to a means for displaying B, or for displaying W in a means for displaying B. The method of driving the electrophoretic element 100-mn is the same as that of the conventional electrophoretic element except for the following points. That is, any screen display image is formed by providing a plurality of black frames, and the plurality of white frames are displayed in a specific time series order. The number of black frame groups and the number of white frame groups all displayed in succession are different or the same.

The switching of the display state on the screen will be described later. The signal used to turn on the TFT gate 104-mn is sent out from the scanning driver 12A and the pixel electrode 106-mn of the electrophoretic element 100-mn via the data line Dn of the data driver 14A. In the state where the electrophoretic element 100-mn is operated as a black display means by applying B to the electrophoretic element 100-mn by applying a voltage of + 15V), the electrophoretic element 100-mn If a white frame is to be provided on the screen to display W, a signal for turning on the TFT gate 104-mn from the scanning driver 12A is applied to the gate line Gm and the pixel electrode through the data line Dn. At -106-mn, a voltage of -15V is applied from the data driver 14a.

The application of a voltage of -15V to the pixel electrode of the electrophoretic element 100-mn will be described with reference to FIG. The selection signal generation circuit 26A that receives the screen data has a pixel period in the selection line corresponding to the pixel, for example, the selection line 30-n, when the electrophoretic element 100-mn displays white color. While outputting a negative voltage. This causes the pMOS of the voltage selection circuit 28A, for example pMOS 36-n, to be turned on and the data line Dn to output a voltage of -15V.

Therefore, when a voltage of −15 V is applied to the pixel electrode 106-mn of the electrophoretic element 100-mn, positively charged black carbon particles are attracted to the pixel electrode 106-mn, and negative charge is generated. White titanium oxide is pushed toward the counter electrode 122. As a result, the electrophoretic element 100-mn switches its display state from black to white (see FIG. 3 (2)).

In the screen following the screen displaying the white state (the following screen described above), when the electrophoretic element 100-mn should display B, a signal for turning on the TFT gate 104-mn is sent to the scanning driver 12A. Is sent from the data driver 14A to the pixel electrode 106-mn of the electrophoretic element 100-mn via the data line Dn.

The application of the voltage + 15V to the pixel electrode 106-mn of the electrophoretic element 100-mn will be described with reference to FIG. The selection signal generating circuit 26A that receives the screen data provides a black frame so that the electrophoretic element 100-mn displays B on the next screen, and thus, a selection line corresponding to the pixel, for example, a selection line. Output a negative voltage for pixel period at (32-n). This causes the pMOS of the voltage selection circuit 28A, for example pMOS 38-n, to be turned on and a voltage of + 15V to be output to the data line Dn.

Therefore, when a voltage of + 15V is applied to the pixel electrode 106-mn of the electrophoretic element 100-mn, the negatively charged white titanium oxide particles are attracted to the pixel electrode 106-mn and draw a positive charge. The dark black carbon particles are pushed toward the counter electrode 122. As a result, the electrophoretic element 100-mn switches its display state from W to B (Fig. 3 (3)).

In Fig. 3 showing a specific example of driving, the reason why the voltage for white display is applied once when the display is switched from W to B is that the black frame corresponds to 40 frames when the display is switched from W to B. So that an asymmetric condition occurs if the white frame continues for a period corresponding to 20 frames when the display transitions from B to W, so that the voltage for the white display is applied during the period during which 20 frames are displayed. Because. As described above, when the electrophoretic element 100-mn repeatedly switches its display state from W to B and from B to W every screen, the number of black frames for B display and white for W display The number of frames is set to satisfy the above expression (3). Because of this, no DC voltage is applied to the electrophoretic element 100-mn, thereby preventing the occurrence of burn-in problems.

The driving method employed when the electrophoretic element 100-mn switches its display state from W to W and from B to B is as follows. That is, in the case of the driving employed when the electrophoretic element 100-mn switches the display from W to W on a given screen, as shown in (3) of FIG. 3, when W is displayed on a given screen, white The black frame is inserted before the frame or between the white frames on the screen. By driving as above, the number of black frames to be inserted (Tww +) becomes equal to the number of white frames to be inserted after the black frame is displayed. In this case, a voltage is applied to the pixel electrode 106-mn of the electrophoretic element 100-mn by the data driver shown in Fig. 2 to write B by providing a black frame and write W by providing a white frame. Is applied. The voltage application method is the same as that described when explaining the display switching from W to B or from B to W, and thus detailed description is omitted.

Also in the case of the driving employed when the electrophoretic element 100-mn switches the display from B to B on a given screen, as shown in (4) of FIG. 3, a black frame when B is displayed on a given screen. A white frame is inserted (as a transition frame) before or after being displayed on this screen. As described above, the number of black frames to be inserted (Tbb +) becomes equal to the number of white frames to be inserted after the black frame is displayed. In order to record B by providing a black frame and write W by providing a white frame, a voltage is applied to the pixel electrode 106-mn of the electrophoretic element 100-mn, and a method of applying the voltage is a given screen. Is the same as that described when switching from W to W.

As a result of the experiment by the inventors, according to the driving method of the present embodiment as shown in Fig. 4, the electrophoretic element 100-mn inserts a B mark between the W mark and the W mark, and displays the display state at W. When switching to W, not only the charging of the electrophoretic element (100-mn) and the occurrence of image burn-in can be prevented, but also the screen is displayed by application of a negative voltage (voltage for white), so that the microcapsule type electric It was confirmed that the decrease in white luminance (the first afterimage described above) can be prevented as compared with the case where white is maintained by the memory characteristics of the electrophoretic element. In addition, when the display is switched from B to B, by inserting a white display between the B and B displays, the black luminance is increased as compared with the case where black is maintained by the memory characteristics of the microcapsule type electrophoretic device (described above). 1 afterimage) can be prevented.

The state change in the drive of this embodiment is shown in FIG. In FIG. 5, 15V at " 15V / -15V "for " W-> W " is the voltage used to insert the B mark between the W and W marks, and " -15V " The voltage is then used to switch the display from B to W. Also, -15V at -15V / 15V for "B-> B" is the voltage used to insert the W mark between the B and B marks, and "15V" is the W after the mark switches from B to W. The voltage used to switch the display from to B.

As described above, when the transition of display from W to B (number of frames is T1) and W (number of frames is T2) occurs on a given screen, T1 becomes equal to T2 and B to W (frames When the switching of the display of T3) and B (number of frames is 4) takes place on a given screen, T3 becomes equal to T4.

The problem of the second afterimage described is that when the pixel electrode is a small and fine pattern having a size of 100 μm to 150 μm, particles contained in the microcapsules constituting the electrophoretic device are generated by pixel voltages of neighboring electrophoretic devices. It occurs because it is affected by leakage electric field. The second afterimage problem currently occurs even when no voltage is applied to the pixel electrode of the electrophoretic device as long as there is a leakage electric field from the electrophoretic device adjacent to the electrophoretic device.

The occurrence of the second afterimage depends on the difference in charge amount of the different particles included in the microcapsules. It is difficult to make the charge amount of the white particles in the microcapsules equal to the charge amount of the black particles in the microcapsules. According to the evaluation of the electrophoretic display of the present inventors, since the charge amount of the TiO (titanium oxide) particles which are the white particles is larger than the charge amount of the carbon particles which are the black particles, the white particles move earlier than the black particles. Therefore, when microcapsules are sandwiched between pixel electrodes, the surface of the microcapsules becomes white and white particles occupy neighboring pixels (see Fig. 6), which damages the black display at those pixels.

To solve this problem, a white frame to be recorded on the screen is separated from the black frame to be recorded and a frame having a small amount of particle charge, small particle mobility, etc., i.e., a black frame selected based on the inventor's evaluation is the last in the formation of a given screen. A driving method is adopted in which the number of black frames is set to be a specific number. By employing this driving method, although white particles occupy adjacent pixels once, black is recorded next and black particles and white particles are mutually within the microcapsules of the boundary between pixels in terms of local separation. Can be separated (see FIG. 7), and the second afterimage problem can be solved. The reason why the black particles do not occupy the adjacent pixel electrode is considered to be that the charge amount, mobility, etc. of the black particles are smaller than that of the white particles, and the number of frame recordings is optimized.

It is demonstrated that the driving method described above solves the first and second afterimage problems, the image burn-in problem described in the background section. In summary, the frames recorded on the electrophoretic elements are separated from each other and frames with a small amount of particle charge are written last in a given screen formation. When the display is switched from W to W, B is recorded by providing a white frame on the screen so that equation (1) described above is satisfied and providing a black frame displayed before or after W (as a transition frame) to be recorded. In addition, when the display is switched from B to B, W is recorded by providing a black frame on the screen so that the above-described equation (2) is satisfied so as to provide a white frame that exists before or after B that is recorded (as a transition frame). . Also, when the display is switched from W to B on the current screen, and when the display is switched from B to W on the next screen, recording is performed so that the above expression (3) is satisfied.

Therefore, according to the first embodiment, the screen is formed by a predetermined number of white frames and a predetermined number of black frames separated from each other, and B is recorded before or after the recording of W when the display is switched from W to W on a given screen. Since the number of times of frame recording for W and B is set to satisfy equation (1), the first afterimage problem and the image burn-in problem that occur when the display is switched from W to W can be solved. Further, when the display is switched from B to B in a given screen, W is recorded before or after the recording of B, and the number of frame recordings for B and W is set so as to satisfy Equation (2), so that the display in B The first afterimage problem and the image burn-in problem that occur when switching to B can be solved. Also, writing the last black frame on a given screen solves the second afterimage problem.

2nd Embodiment

FIG. 9 is a diagram showing waveforms of voltages applied to counter electrodes in driving an electrophoretic display device according to a second embodiment of the present invention.

The configuration of the electrophoretic display device of the second embodiment differs greatly from that employed in the first embodiment in that the electrophoretic element of the electrophoretic display device is driven using a binary driver. More specifically, the driving method employed in the first embodiment is characterized by the fact that the COM (common) voltage does not swing, i.e., Vcom = 0V, and + 15V, 0V and -15V as the H driver (data driver). It is a dot-inversion driving method that is a ternary driver using ternary voltage. In other words, the ternary driver is a drive driver which keeps the voltage of the counter electrode (COM voltage) at 0V all the time and the voltage of the pixel electrode at -15V for the white frame and + 15V for the black frame. The second embodiment is characterized in using a binary driver instead of a ternary driver as a data driver for driving the electrophoretic element in the manner described below.

More specifically, in driving using the binary driver, the voltage applied to the pixel electrode is + 15V or 0V for both the white frame or the black frame, and when the display is switched by providing the white frame in the above-described manner. The COM voltage is set to 15V, and when switching the display by providing a black frame, the COM voltage swings from 0V to + 15V to get 0V as the COM voltage. By the above configuration, in the case of the white frame, when a voltage of + 15V is applied to the counter electrode (+ 15V shown in solid line in FIG. 9) and a voltage of + 15V is applied to the pixel electrode, the pixel electrode and the counter electrode are separated. When the potential difference becomes 0V and a voltage of + 15V is applied to the counter electrode (+ 15V shown in solid line in FIG. 9) and a voltage of 0V is applied to the pixel electrode, the potential difference between the pixel electrode and the counter electrode is -15V. do.

Further, in the case of a black frame, when a voltage of 0 V is applied to the counter electrode (0 V shown in solid line in FIG. 9) and a voltage of +15 V is applied to the pixel electrode, the potential difference between the pixel electrode and the counter electrode is +15 V. When a voltage of 0 V is applied to the counter electrode (0 V shown by a solid line in FIG. 9) and a voltage of 0 V is applied to the pixel electrode, the potential difference between the pixel electrode and the counter electrode becomes 0 V. FIG. Therefore, even when the binary driver is used, the same driving as that provided by the ternary driver is possible by performing the above-described driving method.

Therefore, according to the second embodiment, by using the binary driver, the same effect as that achieved in the first embodiment can be realized and the cost can be reduced.

Third embodiment

FIG. 10 is a diagram showing a change in driving of the electrophoretic display device according to the third embodiment of the present invention. FIG. It is a figure which shows the waveform explaining the drive of the electrophoretic display apparatus which concerns on 3rd Embodiment of this invention. 12 is a time chart illustrating a luminance state in the electrophoretic display devices according to the first and second embodiments of the present invention. FIG. 13 is a time chart illustrating a luminance state in an electrophoretic display device according to a third embodiment of the present invention. FIG. The configuration of the electrophoretic display device of the third embodiment is the first and second embodiments in that the flickered-diplay state occurring when the screen is switched in the first and second embodiments is prevented. Significantly different from

That is, the electrophoretic display device of the present embodiment has a black frame displayed when the display is switched from W to B in display switching from W (white) to B (black) and again from W (white). Without applying the voltage + V (Vwb), for example + 15V, the intermediate potential (Vwb2), for example + to cause the electrophoretic device to display light gray LG, as shown in Figures 10 and 11 Apply 7.5VΩ and then apply a voltage of -15V while the white frame is displayed. In the display transition from B to W and back to B, the electrophoretic element is applied without applying a voltage + V (Vwb), for example -15V while the white frame is displayed when the display is switched from B to W. An intermediate potential Vbw2, for example + 12V, is applied to display the dark gray DG, and then a voltage of + 15V is applied while the black frame is displayed.

Further, the number T1 of frames to which the intermediate potential Vwb2 is applied and the number T2 of frames to which the intermediate potential Vbw2 is applied are set to satisfy the following equation (4):

Vwb2 x T1 = Vbw2 x T2... (4)

This can suppress the occurrence of DC potential (charge) in the electrophoretic film. The filling can be suppressed by satisfying the above formula (4), but even if the above formula (4) is satisfied, the problem of migration of black particles in the microcapsules cannot be solved, that is, the amount of movement of the black particles in the microcapsules is not the same. . This is because, when the voltage is low, the movement amount of the black particles is small.

In the first and second embodiments, as shown in FIG. 12, when the display is switched from W to B and W, the flashing or flickering glare is white, black and white. Occurs during. However, by using the driving method of the third embodiment, white, light gray, and then white are displayed, which can significantly reduce the unnatural visual effects occurring in the display. In addition, in the first and second embodiments, when the display is switched from B to W and again to B, a flashing, that is, flashing occurs during the display of black, white, and then black. However, by using the driving method of the above-described third embodiment, black, dark grey, and then black are sequentially displayed, so that the unnatural visual effect occurring on the screen can be significantly reduced.

Therefore, according to the third embodiment, not only the same effect as in the first and second embodiments can be obtained, but also the reduction of the platen can be achieved, and hence the display quality can be improved.

Fourth embodiment

Fig. 14 is a diagram showing the configuration of a drive circuit of the microcapsule type electrophoretic display device 10B according to the fourth embodiment of the present invention. FIG. 15 is a schematic diagram showing the configuration of a data driver 14B of the microcapsule type electrophoretic display device 10B according to the fourth embodiment. FIG. 16 is a diagram showing a change in driving the microcapsule type electrophoretic display device 10B according to the fourth embodiment. FIG. 17 is a diagram showing a relationship between an afterimage and an applied voltage in the microcapsule type electrophoretic display device 10B according to the fourth embodiment. FIG. 18 is a diagram showing waveforms for explaining driving of the microcapsule type electrophoretic display device 10B according to the fourth embodiment.

In the microcapsule type electrophoretic display device 10B of the present embodiment, a frame forming a screen is divided into a plurality of negative frame groups and a plurality of plus frame groups, and each display state has the same color (same gray level). The number of negative frames used for the transition is equal to the number of plus frames used for the transition between display states having the same color (same gray level), and switching between display states with different colors (different gray levels), respectively. The number of minus frames used for P is equal to the number of plus frames, each with a different color (different gray levels), and the group of frames for particles with slow mobility in response to electric field changes is finally It is configured to be provided. As shown in Fig. 14, the microcapsule type electrophoretic display device 10B is a microcapsule type electrophoretic device 100-mn (m = 1, 2, ..., M; n = 1, 2, ..., N)) is configured to be driven by the scanning driver 12B and the data driver 14B. The configuration of the electrophoretic display panel itself is the same as that of the conventional electrophoretic display panel shown in FIG. Therefore, in Figs. 14 and 15, the same reference numerals are given to components having the same functions as in the conventional electrophoretic display panel, and their description is omitted.

Each microencapsulated electrophoretic element 100-mn is connected to each scanning line Gm and data line Dn through each of the TFT gates 104-mn. When the scanning driver 12B is composed of pMOS, it functions as a driver for outputting a negative gate voltage to each scanning line Gm. In the total frame used to update the pixels for the microencapsulated electrophoretic device (100-mn), the data driver 14B stores a time series voltage that prevents the application of DC voltage to the microencapsulated electrophoretic device (100-mn). Output to line Dn.

As shown in Fig. 15, the data driver 14B includes a select signal generation circuit 26B and a voltage select circuit 28B. The selection signal generation circuit 26B has a time series voltage in which the total selection circuit 28B is composed of Vwb, Vbg, Vgb = -Vbg, Vgg +, 0V, Vgg- = -Vgg +, Vwg, Vgw =-Vwg, and Vbw = -Vwb. Outputs a selection signal for outputting The voltage selection circuit 28B sends time series data of the voltage determined according to the selection signal to the data line Dn. Vwb is, for example, a voltage of + 15V (used when the display is switched from W to B). Vbg is, for example, a voltage of + 7.5V (used when the display is switched from B to G (gray)). Vgb =-Vbg is, for example, a voltage of -7.5 V (used when the display is switched from G to B). Vgg + is, for example, a voltage of + 7.5V (used when the display is switched to G). Vgg- = -Vgg + is, for example, a voltage of -7.5V (used when the display is switched from G to G). Vwg is, for example, a voltage of + 7.5V (used when the display is switched from W to G). Vgw =-Vwg is, for example, a voltage of -7.5V (used when the display is switched from G to W). Vbw = -Vwb is, for example, a voltage of -15V (used when W is written).

The selection signal is determined according to the pixel data on each screen for the image, and is switched in accordance with the pixels on each screen. That is, each screen is formed of a predetermined number of plus frame groups and a predetermined number of negative frame groups. For example, in FIG. 18, each screen is formed of two plus frame groups and one minus frame group. The selection signals that cause the display to switch from W to W, B to B, and G to G, and also B to W, W to B, W to G, G to W, B to G, and G to B The following condition is generated in a manner that is satisfied (see Figs. 16 and 18). The case where the screen is composed of a positive frame group, a negative frame group, and a positive frame group will be described later.

When the electrophoretic element (100-mn) is driven in a state where W is repeatedly and continuously displayed on a given screen (in the case of the continuous display of W-> W-> W…), a negative frame group is provided on the screen. However, by providing a positive frame group (as a transition frame group) before or after a negative frame group is provided, B is recorded, and a display change to B occurs in an insertion manner (see FIG. 18 (1)). In this case, the voltage applied to the pixel electrode 106-mn of the electrophoretic element 100-mn when B is written is set to Vwb, and the pixel electrode of the electrophoretic element 100-mn when W is written. The voltage applied to 106-mn is set to Vbw = -Vwb, the number of white frames used to record W is set to Tww- and the number of black frames used to record B is set to Tww +. At this time, the setting must satisfy the following equation:

Tww + = Tww-... (5)

In addition, when the electrophoretic element 100-mn is driven in a state where black (B) is repeatedly and continuously displayed on a given screen (in the case of continuous display of B-> B-> B…), a positive frame is displayed on the screen. While providing a group, W is recorded by providing a negative frame group (as a transition frame group) before or after a positive frame group is provided, and a change in display to W occurs in an insertion manner (see FIG. 8 (9)). ). In this case, the voltage applied to the pixel electrode 106-mn of the electrophoretic element 100-mn when W is written is set to Vbw = -Vwb, and the electrophoretic element 100-mn when B is written. The voltage applied to the pixel electrode 106-mn of is set to Vwb, the number of negative frames used to write W is set to Tbb- and the number of plus frames used to write B is set to Tbb +. The setting must satisfy the following equation:

Tbb + = Tbb-... (6)

In addition, when the electrophoretic element 100-mn is driven in a state where gray G is repeatedly and continuously displayed on a given screen (for continuous display of G-> G-> G…), a positive frame is displayed on the screen. By providing a group, by providing a negative frame group (as a transition frame group) before or after a positive frame group is provided, G is recorded, and a change in display to W occurs in an insert manner (see Fig. 8 (4)). . In this case, the voltage applied to the pixel electrode 106-mn of the electrophoretic element 100-mn when W is written is set to Vgg-, and the pixel of the electrophoretic element 100-mn when G is written. The voltage applied to the electrode 106-mn is set to Vgg +, the number of negative frames used to record W is set to Tgg- and the number of positive frames used to record B is set to Tgg +. At this time, the setting must satisfy the following equation:

Tgg + = Tgg-... (7)

Also when the display is changed from W to B on the current screen and the display is changed from B to W on the next screen, the pixel electrode of the electrophoretic element 100-mn when W is recorded to change the display from W to B The voltage applied to the 106-mn is set to Vbw = Vwb, the voltage applied to the pixel electrode 106-mn of the electrophoretic element 100-mn when B is written is set to Vwb, and W is The number of negative frame groups used to record is set to Twb (-) and the number of plus frame groups used to record B is set to Twb (+), and B is recorded to change the indication from B to W. The voltage applied to the pixel electrode 106-mn of the electrophoretic element 100-mn when it is set to Vwb, and to the pixel electrode 106-mn of the electrophoretic element 100-mn when W is written. The applied voltage is set to Vbw and the positive voltage used to write B. Being the number of groups is the number of negative frame groups are used to set and record the W by Tbw (+) is Tbw - is set to (). At this time, the setting must satisfy the following equation:

Twb (+) + Tbw (+) = Tbw (-) + Twb (-). (8)

Also when the display is changed from W to G on the current screen and the display is changed from G to W on the next screen, the pixel electrode of the electrophoretic element (100-mn) when W is recorded to change the display from W to G. The voltage applied to the 106-mn is set to Vgw, and the voltage applied to the pixel electrode 106-mn of the electrophoretic element 100-mn when B is written is set to Vgw = -Vgw, and W The number of negative frame groups used to record is set to Twg (-) and the number of plus frame groups used to record B is set to Twg (+), and B is also used to change the display from B to W. The voltage applied to the pixel electrode 106-mn of the electrophoretic element 100-mn when written is set to Vwg, and the pixel electrode 106-mn of the electrophoretic element 100-mn when W is written. The voltage applied to is set to Vgw, plus the positive voltage used to write B. Being the number of groups is the number of negative frame groups are used to set and record a Tgw W (+) is Tgw - is set to (). At this time, the setting must satisfy the following equation:

Twg (+) + Tgw (+) = Tgw (-) + Twg (-)... (9)

Also when the display is changed from B to G on the current screen and the display is changed from G to B on the next screen, the pixel electrode of the electrophoretic element 100-mn when B is recorded to change the display from B to G. The voltage applied to (106-mn) is set to Vgw, and the voltage applied to the pixel electrode 106-mn of the electrophoretic element 100-mn when B is written is set to Vbg = -Vgb, and W The number of negative frame groups used to record is set to Tbg (-) and the number of plus frame groups used to record G is set to Tbg (+), and B is also used to change the display from G to B. The voltage applied to the pixel electrode 106-mn of the electrophoretic element 100-mn when written is set to Vbg, and the pixel electrode 106-mn of the electrophoretic element 100-mn when B is written. The voltage applied to is set to Vgb, plus the positive voltage used to write B. The number of frame groups is set to Tgb (+) and the number of negative frame groups used to record W is set to Tgb (-). At this time, the setting must satisfy the following equation:

Tbg (+) + Tgb (+) = Tgb (-) + Tbg (-)... 10

However, if the indication switches from W to G and from G to W, and from B to G and from G to B, the voltage is Vgw (+) = -Vgw (+) and Vgb (-) = -Vbg (+ Although the absolute value of the voltage of Vgw is not equal to the absolute value of the voltage of Vgb, or the absolute value of the voltage of Vgg + is equal to the absolute value of the voltage of Vgg-. The reason is that in the changed state shown in Fig. 17, as shown in Fig. 17, the charge amounts of the white particles and the black particles are different from each other, and since the mobility of the white particles and the black particles is not the same, the voltage is the same in the black and white states. This is because afterimages occur. This is also the case when the display is switched from G to G.

Next, operations of the electrophoretic display of the fourth embodiment will be described with reference to FIGS. 4, 6, 7, and 14 to 18. In the driving of the microcapsule type electrophoretic display device 10B according to the fourth embodiment, the driving method for causing the electrophoretic element 100-mn to be switched from W to B or from B to W except for the following matters: Is the same as that employed in the conventional display device. That is, any screen displaying an image is formed by providing a plurality of positive frame groups, and the plurality of negative frame groups are displayed in a specific time series order. For example, as shown in Fig. 18, one plus frame group, one minus frame group, and one plus frame group are arranged in this order in an individual screen.

The operation of switching the screen from the given screen to the second screen, the third screen, and the fourth screen by sequentially changing the display of the screen from B-> W-> B-> W will be described. At the beginning of a period corresponding to a certain number (Twb (+)) plus frames constituting the front part of the second plus frame group for the first screen, a signal for turning on the TFT gate 104-mn is generated by the scanning driver ( 12B) is sent to the gate line Gm, and a voltage of Vwb, for example, a voltage of + 15V, is applied to write B to cause the electrophoretic device 100-mn to display black, and the electrophoretic device 100-mn At the beginning of the period applied to the pixel electrode 106-mn of the second positive frame and corresponding to a certain number of positive frames (frame number Twb (+)) constituting the rear part of the second positive frame group (Fig. 18). A voltage of 0 V is applied to the pixel electrode 106-mn of the electrophoretic element 100-mn to maintain (see (5) of), and then the negative frame group (frame number Tbw (−) for the second screen. At the beginning of the period corresponding to)), the TFT gate 104-mn is A signal of N is sent from the scanning driver 12B to the gate line Gm, and a voltage of Vbw, for example, -15V, is applied to the data driver 14B so that the electrophoretic element 100-mn displays W. Is applied from the data line Dn to the pixel electrode 106-mn of the electrophoretic element 100-mn.

Next, with reference to FIG. 15, a voltage of 0 V and voltage application of Vbw to the pixel electrode 106-mn of the electrophoretic element 100-mn will be described. In order for the electrophoretic element 100-mn to switch the display to W, the selection signal generation circuit 26B that receives the screen data is a period corresponding to a certain number of plus frames of the second group of plus frames on the first screen. A negative voltage is output to select line 38-n at the beginning of. This causes the p-MOS, for example, the pMOS 48-n constituting the voltage selection circuit 28B to be turned on, and a voltage of 0V is output to the data line Dn. Thereafter, a negative voltage is output to a selection line corresponding to the pixel, for example, the selection line 31-n, for a period corresponding to the negative frame group for the second screen. This causes the p-MOS, for example the pMOS 41-n constituting the voltage selector circuit 28B, to be turned on, and the voltage of Vbw to be output to the data line Dn.

Therefore, by applying a voltage of Vbw, for example, -15V, to the pixel electrode 106-nm of the electrophoretic element 100-mn, positively charged black carbon particles are transferred to the pixel electrode 106-mn. Dragged, negatively charged white titanium oxide particles are pushed toward the counter electrode 122. As a result, the electrophoretic element 100-mn switches the display from B to W (see FIG. 18 (5)).

Then, when the electrophoretic element 100-mn switches the display from W to B on the next screen (third screen) subsequent to the screen on which W is displayed after switching (on the second screen), the TFT gate ( 104-mn) is sent from the scanning driver 12B to the gate line Gm, and a voltage of Vwb, for example, a voltage of + 15V is supplied from the data line Dn of the data driver 14B to the pixel electrode. (106-mn).

Referring to Fig. 15, the application of the voltage of Vwb to the pixel electrode 106-mn of the electrophoretic element 100-mn will be described. W displayed by the electrophoretic element 100-mn at the beginning of a period corresponding to a particular number of frames (frame number Twb (+)) constituting the front part of the second plus frame group for the third screen. When the display should be switched from to B, the selection signal generation circuit 26B outputs a negative voltage to the selection line corresponding to the pixel, for example, the selection line 30-n. This causes the pMOS 40-n constituting the voltage selection circuit 28B to be turned ON, and the voltage of Vwb corresponds to a certain number of frames constituting the front part of the second plus frame group for the second screen. At some point. Then, a negative voltage is output from the selection signal generating circuit 26B to the selection line 28-n for a period corresponding to the next specific number of frames constituting the front part of the second plus frame group.

Therefore, by applying a voltage of Vwb, for example, a voltage of + 15V to the pixel electrode 106-mn of the electrophoretic element 100-mn, a negatively charged white titanium oxide particle is pixel electrode 106-mn. Attracted, positively charged black carbon particles are pushed toward the counter electrode 122. As a result, the electrophoretic element 100-mn switches the display from W to B (see (6) in Fig. 18).

Then, when the electrophoretic element 100-mn switches the display from B to W on the next screen (fourth screen) subsequent to the screen on which B is displayed after switching (on the third screen), the TFT gate ( A signal for turning on 104-mn) is sent from the scanning driver 12B to the gate line Gm, and a voltage of Vbw, for example, a voltage of -15V is applied from the data line Dn of the data driver 14B to the pixel electrode. (106-mn).

Referring to Fig. 15, the application of the voltage of Vbw to the pixel electrode 106-mn of the electrophoretic element 100-mn will be described. A selection signal generating circuit for receiving screen data when the display is switched from B being displayed by the electrophoretic element 100-mn by providing a negative frame group (frame number Tbw (-)) for the fourth screen ( 26B outputs a negative voltage to the selection line corresponding to the pixel, for example, the selection line 31-n, during the period corresponding to the negative frame group. This causes the pMOS 41-n constituting the voltage selection circuit 28B to be turned on, and the voltage of Vbw to be output to the data line Dn.

Therefore, by applying a voltage of Vbw, for example, -15V, to the pixel electrode 106-mn of the electrophoretic element 100-mn, positively charged black carbon particles are transferred to the pixel electrode 106-mn. Dragged, negatively charged white titanium oxide particles are pushed toward the counter electrode 122. As a result, the electrophoretic element 100-mn switches the display from B to W (see FIG. 18 (5)).

As described above, when the electrophoretic element 100-mn repeatedly switches the display from W to B and from B to W on all screens, the number of black frames for the B display and the white frame for the W display are shown. The number is set to satisfy the above expression (7). Accordingly, since no DC voltage is applied to the electrophoretic element 100-mn, occurrence of burn-in problem is prevented.

The same problem as above occurs when the indication is switched from G to W and then from W to G, or from G to B and then from B to G. However, an image burn-in problem solving method that occurs when the display is switched from W to B and then from B to W, showing the degree of change, is shown in FIG. It may also be applied to the case where G, or G to B and then B to G, and thus detailed description thereof is omitted.

Provided further description used to apply the method shown in FIG. 16 for reference. That is, Vbw and Vwb applied when the indication is changed from B to W and then from W to B should instead be changed to Vgw and Vwg respectively when the indication is changed from W to G, and the indication is from G to B, respectively. Then, when switching from B to G, it should change to Vgb and Vbg. In addition, Twb (+), Twb (-), Tbw (+), and Tbw (-), which are used when the display transitions from B to W and then from W to B, have the display from G to W and then to W When switching to G it should instead be changed to Twg (+), Twg (-), Tgw (+) and Tgw (-) respectively, and instead when the display switches from G to B then B to G instead Must be changed to Tgb (+), Tbg (-), Tbg (+) and Tbg (-).

Also, in Fig. 15, the selection lines 30-n and 31-n used when the display is switched from W to B and then from B to W are converted from W to G and then to G to W. Instead, it should change to selection lines 32-n and 33-n, respectively, and when the display switches from G to B, then to selection lines 34-n and 35-n. . In addition, the pMOSs 42-n and 43-n used when the display is switched from B to W and then from W to B are respectively replaced when the display is switched from G to W and then from W to G, respectively. It should be changed to pMOS 42-n and 43-n, and when the display is switched from G to B and then from B to G, it should instead be changed to pMOS 44-n and 45-n.

The driving method for causing the electrophoretic element 100-mn to switch the display from W to W or for the electrophoretic element 100-mn to switch the display from B to B is as follows: In FIG. As shown, when the electrophoretic element 100-mn switches the display from W to W, if W is displayed on all screens, the first plus frame group is selected before a negative frame group is provided for the screen. By providing B is recorded. The number of frames Tww + constituting the first plus frame group provided as described above is set equal to the number of frames Tww- constituting the first negative frame group provided after the first plus frame group. In this case, when B is written by providing the first plus frame group and W is written by providing the negative frame group, a voltage is applied to the pixel electrode 106-mn of the electrophoretic element 100-mn. The method of applying the voltage is the same as described in the case where the display is switched to a different color (gray level), and thus the detailed description thereof is omitted.

Also, as shown in Fig. 18 (9), when B is displayed on a separate screen when the electrophoretic element 100-mn switches the display from B to B, by providing a negative frame group on the screen, W is recorded. The number Tbb + provided as described above is set equal to the number Tbb− of the frames constituting the provided first negative frame group. The method of applying the voltage to the pixel electrode 106-mn when W is written by providing a positive frame group and W is written by providing a negative frame group is the same as when the display is switched from W to W.

Also, as shown in Fig. 18 (4), when G is displayed on a separate screen when the electrophoretic element 100-mn switches the display from G to G, by providing a negative frame group on the screen, G is recorded. The number Tgg + provided as described above is set equal to the number Tgg− of the frames constituting the first negative frame group provided after the first plus frame group provided is provided. In this case, the voltage is applied to the pixel electrode 106-mn of the electrophoretic element 100-mn when G is written by providing the first plus frame group and when G is written by providing the negative frame group. . The voltage application method is the same as when the display is switched from W to W.

As a result of the experiment by the inventor, according to the driving method of the present embodiment, as shown in Fig. 18, when the electrophoretic element 100-mn switches its display state from W to W, between the W display and the W display. By inserting the B mark, it is possible to prevent the occurrence of charging and image burn-in in the electrophoretic element 100-mn, and also because the screen is displayed by application of a negative voltage (voltage against white), the microcapsule type It was confirmed that the decrease in the white luminance (the first afterimage) can be prevented as compared with the conventional case in which the white state is maintained by the memory characteristic of the electrophoretic device. Further, when the display is switched from B to B, by inserting the W mark between the B mark and the B mark, the black luminance is increased compared with the conventional case where the black state is maintained by the memory characteristics of the microcapsule type electrophoretic element. (The first afterimage) can be prevented. In addition, it was experimentally confirmed that the same effect can be obtained by inserting the W mark between the G mark and the G mark when the display is switched from G to G.

The second afterimage problem described above is that when the pixel electrode is a small and fine pattern having a size of 100 µm to 150 µm, the leakage electric field generated by the pixel voltage of the adjacent electrophoretic element is included in the microcapsules constituting the electrophoretic element. It happens because it is affected by. This problem arises even if no voltage is applied to the pixel electrode of the electrophoretic device as long as there is a leakage electric field from the electrophoretic device adjacent to the electrophoretic device.

The occurrence of the second afterimage depends on the difference in the amount of charge of the different particles contained in the microcapsules. It is difficult to equalize the charge amount of the white particles in the microcapsules with the charge amount of the black particles in the microcapsules. According to the present inventor's electrophoretic display evaluation, since the charge amount of the TiO particles, which are white particles, is larger than the charge amount of the carbon particles, which are black particles, the white particles move earlier than the black particles. Therefore, when microcapsules are sandwiched between pixel electrodes, the surface of the microcapsules becomes white and white particles occupy neighboring pixels (see Fig. 6), which damages the black display at those pixels.

To solve this problem, a white frame to be recorded on the screen is separated from the black frame to be recorded and a frame having a small amount of particle charge, small particle mobility, etc., i.e., a black frame selected based on the inventor's evaluation is the last in the formation of a given screen. A driving method is adopted in which the number of black frames is set to be a specific number. By employing this driving method, although white particles occupy adjacent pixels once, black is recorded next and black particles and white particles are separated from each other in microcapsules at the boundary between pixels in terms of local separation. (See FIG. 7), the second afterimage problem can be solved. The reason why the black particles do not occupy the adjacent pixel electrode is considered to be that the charge amount, mobility, etc. of the black particles are smaller than that of the white particles, and the number of frame recordings is optimized.

It is demonstrated that the driving method described above solves the first and second afterimage problems, the image burn-in problem described in the background section. In summary, the frames recorded on the electrophoretic elements are separated from each other and frames with a small amount of particle charge are written last in a given screen formation. When the display is switched from W to W, B is recorded by providing a white frame on the screen so that equation (5) described above is satisfied and providing a black frame displayed before or after W (as a transition frame) to be recorded. Further, when the display is switched from B to B, W is recorded by providing a black frame on the screen so as to satisfy the above equation (6) so as to provide a white frame which exists before or after B (as a transition frame) to be recorded. . Also, when the display is switched from W to B on the current screen, and when the display is switched from B to W on the next screen, recording is performed so that the above expression (7) is satisfied.

Also, when the display is switched from W to B on the current screen and the display is switched from B to W on the next screen, the driving method is performed so that the above expression (8) is satisfied. When the display is switched from W to G on the current screen and the display is switched from G to W on the next screen, the driving method is performed so that the above expression (9) is satisfied. When the display is switched from B to G on the current screen and the display is switched from G to B on the next screen, the driving method is performed so that the above expression (10) is satisfied.

Therefore, according to the fourth embodiment, the provision of one negative frame group is inserted between two positive frame group provisions when B is formed and the display is repeatedly and successively switched from W to W, and B is Since the driving operation is performed so that the number of frames for W and the number of frames for B are set to satisfy the above expression (5), the first afterimage and the image that occurred in continuous switching for W are recorded before being recorded. Burn-in can be avoided. Further, when the display is repeatedly and continuously switched from B to B, W is recorded after B is recorded so that the number of B and W frames satisfies Equation (6) above, so that the driving method employed is continuous B. To solve the first afterimage and image burn-in caused by the conversion. In addition, when the display is repeatedly and continuously switched from G to G, W is recorded after G is recorded so that the number of G and W frames satisfies Equation (7). The first afterimage and the image burn-in caused by the conversion of G are solved.

In addition, when the display is switched repeatedly and continuously between different colors (gray levels), that is, W, B and G, the number of frames to be recorded is driven to satisfy the above expressions (8), (9), and (10). The method is performed and the problem caused by the continuous display switching between different colors can be solved. In addition, the second afterimage can be avoided by recording the black frame group last in the screen formation.

5th embodiment

19 is a diagram showing a change in display state in driving an electrophoretic display device according to a fifth embodiment of the present invention. 20 is a time chart illustrating driving of a microcapsule type electrophoretic display device according to a fifth embodiment. The driving method of the fifth embodiment differs greatly from that employed in the fourth embodiment in that the microcapsule type electrophoretic display is driven at four gray levels instead of three gray levels. That is, in the microcapsule type electrophoretic display device (not shown in FIG. 19) of the present embodiment, the half-tone and gray G employed in the fourth embodiment are light gray LG and dark gray. (DG), and the same driving method as that performed in the fourth embodiment is carried out in the switching between W, B, and LG and in the switching between W, B, and DG, and is performed for display switching between LG and DG. The driving method is as follows.

That is, when the display is to be switched between LG and DG, as shown in Fig. 19, the display is switched to W once. After the display is first switched from LG to W and then to DG, the display is switched from DG to W and then to LG to avoid the difficulty of voltage regulation. This allows the drive waveform and voltage to be used in the same manner as when the display is switched from LG to W and from W to DG.

In the display switching from DG to LG and from LG to DG, when the display is switched from DG to LG and then to DG, W is recorded between LG and DG and then from DG to W to LG, and LG To W and then to DG. In this case, in order to switch the display from DG to W, the voltage applied to the pixel electrode 106-mn of the electrophoretic element 100-mn is set to Vw + dg (+), for example + 1.2V. The number of frames provided at this voltage is set to Tw-dg (+). In order to switch the display from W to LG, the voltage applied to the pixel electrode 106-mn of the electrophoretic element 100-mn is set to Vw-lg (-), for example -5V, at which voltage The number of frames provided is set to Tw-lg (-). Also, in order to switch the display from LG to W, the voltage applied to the pixel electrode 106-mn of the electrophoretic element 100-mn is set to Vw-lg (+), for example, + 5V, and this voltage The number of frames provided by is set to Tw-lg (+). In addition, in order to switch the display from W to DG, the voltage applied to the pixel electrode 106-mn of the electrophoretic element 100-mn is set to Vw-dg (−), for example, −12V. The number of frames provided by the voltage is set to Tw-lg (-).

The number and voltage of frames to be used when the display switches from DG-> LG-> DG are expressed as follows, and adjustments are made to satisfy the following equation:

Vw-dg (−) =-Vw-dg (+), Vw-lg (-) =-Vw-lg (+). (11)

Tw-dg (+) = Tw-dg (-), Tw-lg (+) = Tw-lg (-). (12)

Further adjustments are made so that the absolute values of the voltage values Vw-dg and Vw-lg do not cause an afterimage, and an image is displayed at a specific gray level to drive the electrophoretic display.

Next, the operation of the electrophoretic display of the fifth embodiment will be described with reference to FIGS. 19 and 20. In this embodiment, the image is represented by four gray levels, namely W, B, LG and DG. The driving method for displaying an image at three gray levels, that is, W, B and LG, and three gray levels, that is, W, B, and DG when the image is displayed at four gray levels is the same as that described in the fourth embodiment. . Therefore, a driving method for switching the display between LG and DG at four gray levels will be described later.

When driving to switch the display from LG to DG and from DG to LG, the record of W is inserted between the record of LG and DG so that the display is DG-> W-> LG and LG-> W-> Switch to DG. When driving is performed to switch the display from DG to LG, the voltage of Vw-dg (+) is increased during the period corresponding to the frame number Tw-dg (+) to switch the display from DG to W. -mn) is applied to the pixel electrode. Then, to switch the display from W to LG, a voltage of Vw-lg (-) is applied to the pixel electrode of the electrophoretic element 100-mn for a period corresponding to the number of frames Tw-lg (-). . The authorization causes display switching from DG to LG.

Also, when a drive is performed to switch the display from LG to DG, the voltage of Vw-dg (+) is increased during the period corresponding to the frame number Tw-dg (+) to switch the display from LG to W. Is applied to a (100-mn) pixel electrode. Then, in order to switch the display from W to DG, a voltage of Vw-dg (-) is applied to the pixel electrode of the electrophoretic element 100-mn for a period corresponding to the number of frames Tw-dg (-). . By the authorization, display switching from LG to DG occurs.

When the display switches from DG-> LG-> DG, adjust so that the voltage and frame number satisfy the above formulas (11) and (12) and the absolute value on the screen of the voltages Vw-dg and Vw-lg does not cause an afterimage This is done and the image is displayed at a particular gray level. A specific example of the above-described driving is shown in FIG. FIG. 20 (1) shows waveforms for driving to switch the display from DG to LG, and (2) shows waveforms for driving to switch the display from LG to DG.

Therefore, according to the fifth embodiment, the driving method employed in the fourth embodiment is applied when the display is switched between W, B and LG, and between W, B and DG, and the display switching between DG and LG. The driving for is performed so that the above equations (11) and (12) are satisfied and the absolute values of the voltages Vw-dg and Vw-lg do not cause afterimages, and the image is represented in four graph levels. Even when displayed in gray levels, the afterimage and burn-in problems on the screen are solved.

6th embodiment

FIG. 21 is a diagram showing a change in driving the microcapsule type electrophoretic display device according to the sixth embodiment of the present invention. 22 is a diagram showing waveforms for explaining driving of the microcapsule type electrophoretic display device according to the sixth embodiment. 23 is a timing chart for explaining the disadvantages of the fourth and fifth embodiments. 24 is a timing chart illustrating the advantages of the sixth embodiment of the invention. The configuration of the microcapsule type electrophoretic display device of the sixth embodiment differs greatly from the fourth and fifth embodiments in that the flashing display state occurring when the screen is switched in the fifth embodiment is prevented.

That is, in the electrophoretic display device of the sixth embodiment, when the display is switched from W-> B-> W, the voltage used to provide a positive frame group when the display is switched from W to B is + V ( Vwb), for example, is not set to + 15V, and as shown in Figs. 21 and 22, the intermediate potential Vwb2, for example + 7.5V, for causing the electrophoretic element to display light gray LG, When a voltage of -15V generated after application is applied, and the display transitions from B-> W-> B, the voltage used to provide a negative frame group when the display transitions from B to W is -V ( Vwb), for example, is not set to -15V, but a voltage of + 15V generated after the application of an intermediate potential Vbw2, for example + 12V, for causing the electrophoretic element to display dark gray (DG) is applied. do. Further, when the display is switched from G-> W-> G, the voltage used when the display is switched to W is not applied, but the voltage generated after the intermediate potential is applied is applied. However, for the sake of simplicity, the display switched from G-> W-> G is not shown in Figs.

Further, in any one of the display switching cases described above, the number T1 of frames provided when the intermediate potential of Vwb2 is applied and the number T2 of frames provided when the intermediate potential Vbw2 are applied should be set to satisfy the following equation. :

Vwb2 x T1 = Vbw2 x T2... (13)

This makes it possible to suppress the generation (charge) of the DC potential in the electrophoretic film. The filling can be suppressed by satisfying the above formula (13), but even when the above formula (13) is satisfied, there is a problem that the black particles in the microcapsules, that is, the amount of black particles in the microcapsules are not the same Not solved. This is because the movement amount of the black particles is small when the voltage is low.

In the fourth and fifth embodiments, as shown in Fig. 23, when the display is switched from W-> B-> W, the flashing, i.e., the unnatural feeling, is the display of W, B and W. Occurs in However, by driving the electrophoretic display according to the method employed in the sixth embodiment, LG is displayed after W is displayed as shown in Fig. 24, and then W is displayed so that the unnatural feeling in the display is significantly reduced. Can be. Also in the fourth and fifth embodiments, when the display is switched from B-> W-> B, a flashing, i.e., flashing (unnatural feeling) occurs in black, white and then black display. However, by driving the electrophoretic display according to the method employed in the sixth embodiment, as shown in Fig. 24, DG is displayed after B is displayed, and then B is displayed so that the unnatural feeling in the display is significantly reduced. Can be. Therefore, according to the sixth embodiment, not only the same effects as those obtained in the fourth and fifth embodiments, but also the reduction of the platen can be achieved.

It is apparent that the present invention is not limited to the above embodiments and can be changed or modified without departing from the scope and spirit of the present invention. For example, in each of the above embodiments, it is necessary to satisfy Equations (1) and (5) when the display is switched from W-> W-> W, and the display on the screen is B-> B-> B. It is necessary to satisfy Equations (2) and (6) when switching to, and it is necessary to satisfy Equation (7) when the display is switched from G to G to G on the screen. This is not required and some discrepancies are allowed. Similarly, it is necessary to satisfy Equations (3) and (13) when the display is switched between W-> B-> B-> W between the screens, but satisfying these conditions is not necessarily required and a little Inconsistency is allowed. Similarly, it is necessary to satisfy Equations (3) and (8) when the display is switched between W-> B-> B-> B between the screens, and the display between the screens is W-> G-> G- Equation (9) needs to be satisfied when switching to> W, and it is necessary to satisfy Equation (10) when the display is switched between B-> G-> G-> B between screens, but these conditions Satisfaction is not required and some discrepancies are allowed. It is also necessary to satisfy Equations (11) and (12) when the display is switched between DG-> LG-> DG between screens, but satisfying these conditions is not required and some discrepancies are allowed. . Regardless of whether the above equation is satisfied, the present invention can be carried out by appropriately selecting a low difference based on the charged particle material or the intermediate color tone to be displayed. In the above embodiments, the white charged particles and the black charged particles sealed in the microcapsules of the electrophoretic display were used, but the present invention can be carried out using charged particles having colors other than white and black. In this case, the potential difference applied between the pixel electrode and the large electrode of the microcapsule type electrophoretic device changes depending on the particles sealed in the microcapsules. Naturally, the potential difference for displaying the halftone between the two colors also changes. Also in the above embodiment, in the PET counter substrate, one counter electrode is fixed to the transparent plastic substrate, but the present invention can be performed by constructing the PET counter substrate with counter substrates arranged in all scanning directions.

In addition, the microcapsule type electrophoretic display element driving method may be applied to various display devices, for example, an information processing device, a personal digital device (PDA), a video camera, and the like.

According to the present invention, an electrophoretic display device capable of preventing afterimages, image burn-in, and flashing can be obtained.

Claims (42)

An electrophoretic panel and a potential difference applying unit, The electrophoretic panel, A plurality of signal lines extending parallel to each other in a first direction, a plurality of scanning lines extending parallel to each other in a second direction perpendicular to the first direction, and a plurality of pixel electrodes as electrophoretic elements, one of the signal lines And a first substrate arranged in a one-to-one relationship corresponding to each intersection point of one of the scanning lines, A second substrate having a transparent counter electrode facing the plurality of pixel electrodes, and A first color charged particle having a first color and a first polarity sandwiched movably between each of the plurality of pixel electrodes and the transparent opposing electrode such that the pixels are arranged in a matrix form and having a second color and a second polarity A second color charged particle; The potential difference applying unit, When each of a plurality of pictures including a first pattern having the first color and a second pattern having the second color is displayed in a display area of the electrophoretic display panel, the first pattern and the first pattern are displayed. Applying a potential difference corresponding to each of the first color and the second color during a period corresponding to a predetermined number of frames between at least one pixel electrode corresponding to each of the two patterns and the transparent counter electrode, Providing a first frame group consisting of a predetermined number of first frames and corresponding to the first color and a second frame group consisting of a predetermined number of second frames and corresponding to the second color in a predetermined order for each screen. First means; And In displaying the screen, when the first frame group is generated by the first means, the first frame group with respect to the first frame group is formed between each of the pixel electrodes corresponding to the first pattern and the transparent counter electrode. A potential difference corresponding to one color is applied, and when the second frame group is generated by the first means, between each of the pixel electrodes corresponding to the second pattern and the transparent opposing electrode; And second means for applying a potential difference corresponding to the second color with respect to the second color. The method of claim 1, The second means is adapted to obtain the given screen between each of the corresponding pixel electrodes and the opposite electrode when any one of the first and second colors to be displayed on the given screen should be displayed continuously on a subsequent screen. A potential difference corresponding to another one of the first and second colors in a transition state between any one of the provided first frame group and the second frame group and the any one frame group provided to obtain the subsequent picture As a third means for applying a power source, wherein the potential difference corresponds to another color whose polarity is opposite to the potential difference corresponding to the one color and corresponds to another frame group of the first frame group and the second frame group. And further comprising said third means applied. The method of claim 1, The second means is an electrophoretic element, wherein the number of frames required for one or more of the pixel electrodes to display any one of the first and second colors on a given screen is given the one one color. And fourth means for equalizing the number of frames required for the one pixel electrode displayed on the screen to display a color different from the one of the first and second colors on a subsequent screen, Electrophoretic display. The method of claim 3, wherein The fourth means is a number T1 of frames necessary for causing the one pixel electrode to display the arbitrary one color on the first screen, and the one pixel electrode displaying the arbitrary one color on the first screen. The number of frames T2 necessary for causing the second screen to be displayed on the second screen subsequent to the first screen, and the first pixel electrode displaying the other color on the second screen is followed by the second screen. The number T3 of frames required to display the different colors on three screens, and one or more pixel electrodes displaying the different colors on the third screen display the one color on a fourth screen subsequent to the third screen. The number of frames required to display T2 + T3 = T1 + T4 An electrophoretic display device which is driven to hold. The method of claim 1, The second means is configured to move one frame group of the first frame group and the second frame group toward the counter electrode in response to a change in an electric field to form the last frame group in forming the screen. And a fifth means for setting to the electrophoretic display device. The method of claim 1, The second means transitions an intermediate potential difference between a potential difference applied before switching of the screen and a potential difference applied after switching, when the potential difference between at least one of the pixel electrodes and the counter electrode changes during the switching of the screen. And a sixth means for applying in a state. The method of claim 6, The sixth means includes an intermediate potential difference V1 applied between at least one of the pixel electrodes and the counter electrode when the one of the pixel electrodes switches the display from any one of the first and second colors to another color. Applies a potential potential difference V2 applied between the one of the pixel electrodes and the opposing electrode when the number T1 of frames to apply T1 and the one of the pixel electrodes switches the display from the other color to the any one color; The following expression between the number of frames T2 V1 x T1 = V2 x T2 The electrophoretic display device is configured to establish. The method of claim 1, In the electrophoretic display panel, each pixel electrode on the first substrate is connected to each signal line through a respective gate element controlled by a signal supplied from each scanning line, and the second substrate Has a piece of said transparent opposing electrode opposite the entire area of said first substrate, wherein said first color charged particles and said second color charged particles are dispersed in a binder between said first substrate and said second substrate. An electrophoretic display device suspended in a dispersant sealed in each capsule. The method of claim 1, Wherein the first color comprises any one of black and white and the second color comprises the other of black and white. The method of claim 1, And the second means used to apply the potential difference is a ternary driver that fixes the potential of the opposite electrode to a reference potential and changes the potential of the pixel electrode by the potential difference from the reference potential. . The method of claim 1, The second means used for applying the potential difference changes the potential of the counter electrode from the reference potential according to the first color or the second color by the potential difference, and changes the potential of the counter electrode with the counter electrode according to the potential change of the counter electrode. And a binary driver for changing a potential of the pixel electrode to generate a potential difference corresponding to the first color or the second color between the pixel electrodes. A method of driving an electrophoretic display device comprising an electrophoretic panel, The electrophoretic panel, A plurality of signal lines extending parallel to each other in a first direction, a plurality of scanning lines extending parallel to each other in a second direction perpendicular to the first direction, and a plurality of pixel electrodes as electrophoretic elements, one of the signal lines And a first substrate arranged in a one-to-one relationship corresponding to each intersection point of one of the scanning lines, A second substrate having a transparent opposing electrode facing the plurality of pixel electrodes, and A first color charged particle having a first color and a first polarity sandwiched movably between each of the plurality of pixel electrodes and the transparent opposing electrode such that the pixels are arranged in a matrix form, and a second color and second polarity A second color charged particle having When each of the plurality of screens including the first pattern having the first color and the second pattern having the second color is displayed in the display area of the electrophoretic display panel, the first pattern and the second pattern A potential difference corresponding to each of the first color and the second color is applied between a corresponding one or more pixel electrodes and the transparent counter electrode for a period corresponding to a predetermined number of frames, The driving method, Providing a first frame group consisting of a predetermined number of first frames and corresponding to the first color, and a second frame group consisting of a predetermined number of second frames and corresponding to the second color in a predetermined order for each screen. Doing; And In displaying the screen, when the first frame group is generated by the first unit, the first frame group with respect to the first frame group is formed between each of the pixel electrodes corresponding to the first pattern and the transparent counter electrode. A potential difference corresponding to one color is applied, and when the second frame group is generated by the first unit, the second frame group is disposed between each of the pixel electrodes corresponding to the second pattern and the transparent counter electrode. And applying a potential difference corresponding to the second color with respect to the second color. The method of claim 12, When any one of the first and second colors to be displayed on a given screen should be displayed continuously on a subsequent screen, between each of the corresponding pixel electrodes and the opposite electrode, the Apply a potential difference corresponding to the other of the first and second colors in a transition state between any one frame of the first frame group and the second frame group and the one frame group provided to obtain the subsequent picture Wherein the potential difference corresponds to the other color whose polarity is opposite to the potential difference corresponding to the one color and is applied for a period corresponding to another frame group of the first frame group and the second frame group. Method of driving the display device. The method of claim 12, The number of frames required for one or more of the pixel electrodes as electrophoretic elements to display any one of the first and second colors on a given screen is the one in which the one color is displayed on a given screen. And the number of frames required for causing the pixel electrode of to display a color different from the one of the first and second colors on a subsequent screen. The method of claim 14, The number of frames T1 required for causing the one pixel electrode to display the arbitrary one color on the first screen, and the one pixel electrode displaying the arbitrary one color on the first screen is displayed on the first screen. The number of frames T2 required to cause the other color to be displayed on a subsequent second screen, wherein the one pixel electrode displaying the other color on the second screen is different from the third screen subsequent to the second screen. The number of frames T3 required to display the color, and the one pixel electrode displaying the different color on the third screen is needed to display the arbitrary one color on a fourth screen subsequent to the third screen. The following formula between the number of frames T4, T2 + T3 = T1 + T4 The driving method of this electrophoretic display apparatus is established. The method of claim 12, Electrophoresis, which sets one frame group of the first frame group and the second frame group to move the charged particles having slow mobility toward the counter electrode in response to the change of the electric field to the last frame group in forming the screen Method of driving the display device. The method of claim 12, When the potential difference between at least one of the pixel electrodes and the counter electrode changes during the switching of the screen, the intermediate potential difference between the potential difference applied before switching of the screen and the potential difference to be applied after switching is shifted among the pixel electrodes. And applying between the one and the counter electrode. The method of claim 12, Of the frame applying an intermediate potential difference V1 applied between at least one of the pixel electrodes and the opposite electrode when the one of the pixel electrodes switches the display from any one of the first and second colors to another color. A number T1 and the number of frames T2 that apply an intermediate potential difference V2 applied between the one of the pixel electrodes and the opposite electrode when the one of the pixel electrodes switches the display from the other color to the any one color. Between the following expressions, V1 x T1 = V2 x T2 The driving method of this electrophoretic display apparatus is established. The method of claim 12, In the electrophoretic display panel, each pixel electrode on the first substrate is connected to each signal line through a respective gate element controlled by a signal from each scanning line, and the second substrate is Each of said first and second color charged particles having a piece of said transparent opposing electrode facing the entire area of said first substrate, wherein said first color charged particles and said second color charged particles are dispersed in a binder between said first substrate and said second substrate. A method of driving an electrophoretic display device, which is suspended in a dispersant sealed in a capsule. The method of claim 12, And the first color comprises any one of black and white and the second color comprises the other of black and white. An electrophoretic display panel and a potential difference applying means, The electrophoretic display panel, A plurality of signal lines extending parallel to each other in a first direction, a plurality of scanning lines extending parallel to each other in a second direction perpendicular to the first direction, and a plurality of pixel electrodes as electrophoretic elements, one of the signal lines And a first substrate arranged in a one-to-one relationship corresponding to each intersection point of one of the scanning lines, A second substrate having a transparent opposing electrode facing the plurality of pixel electrodes, and A first color charged particle having a first color and a first polarity sandwiched movably between each of the plurality of pixel electrodes and the transparent opposing electrode such that the pixels are arranged in a matrix form, and a second color and second polarity A second color charged particle having The potential difference applying means, Each of the plurality of screens includes a first pattern having the first color, a second pattern having the second color, and at least one halftone pattern having a midtone color between the first color and the second color. When displayed in a display area of the electrophoretic display panel, the first period of time corresponds to a predetermined number of frames between at least one pixel electrode corresponding to each of the first pattern and the second pattern and the transparent counter electrode. Applying a potential difference corresponding to each of the color, the second color, and the one half tone pattern, A plurality of frame groups each consisting of a predetermined number of predetermined frames are generated for each of the screens, and the potential difference for each of the first color, the second color, and the mid-tone color to be displayed in the display area is output in a predetermined order. First means for doing, and Each of the pixel electrodes corresponding to the first pattern, the second pattern or the one mid-tone pattern in any one of the plurality of frame groups sequentially generated by the first means in displaying the screen And second means for applying a potential difference of each of the frame groups between the counter electrode and the counter electrode. The method of claim 21, The second means is further adapted for each of said corresponding pixel electrodes and said when any one of said first color, second color and said one mid-tone color to be displayed on a given screen is to be displayed continuously on a subsequent screen; Between any one color and in transition state between an opposing electrode, any one frame group corresponding to said one color provided to obtain said given screen and said any one frame group provided to obtain said subsequent screen; As a third means for applying a potential difference corresponding to a different other color, the potential difference corresponding to another color whose polarity is opposite to that of the potential difference corresponding to the any one color and corresponding to another frame group different from the any one frame group And the third means applied for a period of time. The method of claim 21, The second means is characterized in that the number of frames required to apply a predetermined potential difference to at least one of the pixel electrodes as an electrophoretic element on a given screen is determined by the predetermined one of the pixel electrodes to which the predetermined potential difference is applied on a subsequent screen. And a fourth means for equalizing the number of frames required for applying an opposite potential difference having a polarity opposite to the potential difference. The method of claim 23, The fourth means includes the number T1 of frames required to apply the predetermined potential difference to the one or more pixel electrodes on a first screen, the one or more pixel electrodes to which the predetermined potential difference is applied on a second screen subsequent to the first screen. The counter potential difference is continued to the one of the number of frames T2 required for applying the counter potential difference having the opposite polarity to the predetermined potential difference to the pixel electrode to which the counter potential difference is applied on the third screen subsequent to the second screen. Between the number T3 of frames required for application and the number T4 of frames required for applying the predetermined potential difference to the one of the pixel electrodes to which the opposite potential difference is applied on the fourth screen subsequent to the third screen. , T2 + T3 = T1 + T4 An electrophoretic display device which is driven to hold. The method of claim 21, The second means for setting one frame group of the plurality of frame groups as the last frame group at the time of forming the screen, which moves charged particles having slow mobility toward the counter electrode in response to a change in electric field An electrophoretic display device further comprising means. The method of claim 21, The second means transitions an intermediate potential difference between a potential difference applied before switching of the screen and a potential difference applied after switching, when the potential difference between at least one of the pixel electrodes and the counter electrode changes during the switching of the screen. And a sixth means for applying in a state. The method of claim 26, And the sixth means is adapted to switch the pixel electrode when the one of the pixel electrodes switches the display from any one of the first color, the second color and the one or more halftone colors to another color different from the any one color. The number of frames T1 applying an intermediate potential difference V1 applied between at least one of the and the counter electrode, and the one of the pixel electrodes when the one of the pixel electrodes switches display from the other color to the any one color; The following equation between the number T2 of the frames applying the intermediate potential difference V2 applied between one and the opposite electrode, V1 x T1 = V2 x T2 The electrophoretic display device is configured to establish. The method of claim 21, In the electrophoretic display panel, each pixel electrode on the first substrate is connected to each signal line through a respective gate element controlled by a signal from each scanning line, and the second substrate is Each of the first color charged particles and the second color charged particles having a piece of transparent opposing electrode facing the entire area of the first substrate, the first color charged particles and the second color charged particles dispersed in a binder between the first substrate and the second substrate; An electrophoretic display device suspended in a dispersant sealed in a capsule. The method of claim 21, Wherein the first color comprises any one of black and white, the second color comprises the other one of black and white, and the one mid-tone color comprises gray. The method of claim 21, The first color comprises any one of black and white, the second color comprises the other one of black and white, and the mid-tone color comprises light gray and dark gray Electrophoretic display device. The method of claim 30, The switching of the display between the light gray and the dark gray is performed in such a manner that a white display is inserted between the display of the light gray and the display of the dark gray. A method of driving an electrophoretic display device comprising an electrophoretic panel, The electrophoretic panel, A plurality of signal lines extending parallel to each other in a first direction, a plurality of scanning lines extending parallel to each other in a second direction perpendicular to the first direction, and a plurality of pixel electrodes as electrophoretic elements, one of the signal lines And a first substrate arranged in a one-to-one relationship corresponding to each intersection point of one of the scanning lines, A second substrate having a transparent opposing electrode facing the plurality of pixel electrodes, and A first color charged particle and a second color and a second polarity having a first color and a first polarity sandwiched in a movable manner between each of the plurality of pixel electrodes and the transparent opposing electrode such that the pixels are arranged in a matrix form A second color charged particle having Each of the plurality of screens comprising a first pattern having the first color, a second pattern having the second color, and at least one halftone pattern having a midtone color between the first color and the second color; When displayed in a display area of an electrophoretic display panel, the first period of time corresponds to a predetermined number of frames between the at least one pixel electrode and the transparent counter electrode corresponding to each of the first pattern and the second pattern. A potential difference corresponding to each of the color, the second color, and one halftone pattern is applied, The driving method, Generating a plurality of frame groups composed of a predetermined number of predetermined frames per screen, and outputting the potential difference for each of the first color, the second color, and the mid-tone color to be displayed in the display area in a predetermined order; Steps, and Each of the pixel electrodes corresponding to the first pattern, the second pattern, or the one mid-tone pattern in any one of the plurality of frame groups sequentially generated by the first unit in displaying the screen And applying a potential difference of each of the frame groups between an electrode and the counter electrode. The method of claim 32, When any one of the first color, the second color and the one mid-tone color to be displayed on a given screen should be displayed continuously on a subsequent screen, between each corresponding pixel electrode and the opposite electrode, the given Potential difference corresponding to another color different from the one color in transition state between any one frame group corresponding to the one color provided to obtain a picture and the one frame group provided to obtain the subsequent picture Wherein the potential difference is applied for a period corresponding to the other color whose polarity is opposite to the potential difference corresponding to the one color and corresponding to another frame group different from the one frame group. Method of driving. The method of claim 32, The number of frames required for applying a predetermined potential difference to at least one of the pixel electrodes as an electrophoretic element on a given screen has a polarity opposite to the predetermined potential difference to the one of the pixel electrodes to which the predetermined potential difference is applied on a subsequent screen. A method of driving an electrophoretic display device, which is equal to the number of frames required to apply an opposite potential difference. The method of claim 34, wherein The number of frames T1 required to apply the predetermined potential difference to the at least one pixel electrode on a first screen, and the predetermined potential difference to the one of the pixel electrodes to which the predetermined potential difference is applied on a second screen subsequent to the first screen. The number of frames T2 required to apply the opposite potential difference having the opposite polarity, the frame required to subsequently apply the opposite potential difference to the one of the pixel electrodes to which the opposite potential difference is applied on the third screen subsequent to the second screen. Between the number T3 and the number T4 of frames required to apply the predetermined potential difference to the one of the pixel electrodes to which the opposite potential difference is applied on the fourth screen subsequent to the third screen, T2 + T3 = T1 + T4 The driving method of this electrophoretic display apparatus is established. The method of claim 32, A method of driving an electrophoretic display device, in which one frame group of the plurality of frame groups, which moves charged particles having slow mobility toward the counter electrode in response to a change in an electric field, is set as the last frame group in forming the screen. . The method of claim 32, When the potential difference between at least one of the pixel electrodes and the counter electrode changes during the switching of the screen, the pixel electrode in a transition state with an intermediate potential difference between the potential difference applied before the switching of the screen and the potential difference to be applied after the switching A method of driving an electrophoretic display device, which is applied between the one of the and the counter electrode. The method of claim 37, wherein At least one of the pixel electrodes when the one of the pixel electrodes switches the display from any one of the first color, the second color and the one midtone color to another color different from the any one color; The number T1 of frames for applying the intermediate potential difference V1 applied between the opposing electrodes, and the opposing one of the pixel electrodes when the one of the pixel electrodes switches the display from the other color to the arbitrary one color. Between the number T2 of the frames applying the intermediate potential difference V2 applied between the electrodes, V1 x T1 = V2 x T2 The driving method of this electrophoretic display apparatus is established. The method of claim 32, In the electrophoretic display panel, each pixel electrode on the first substrate is connected to each signal line through a respective gate element controlled by a signal from each scanning line, and the second substrate is Each of the first color charged particles and the second color charged particles having a piece of transparent opposing electrode facing the entire area of the first substrate, the first color charged particles and the second color charged particles dispersed in a binder between the first substrate and the second substrate; A method of driving an electrophoretic display device suspended in a dispersant sealed in a capsule. The method of claim 32, Wherein the first color comprises any one of black and white, the second color comprises the other one of black and white, and the one half tone color comprises gray. The method of claim 32, Wherein the first color comprises any one of black and white, the second color comprises the other one of black and white, and the mid-tone color comprises light gray and dark gray. The method of claim 32, The switching of the display between the light gray and the dark gray is performed in such a manner that a white display is inserted between the display of the light gray and the display of the dark gray.

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